I agree with the others that this needs to be kept transparent but I'm wondering if seeing the names should be a privilege that is earned.
What if this was a privilege earned at the remove new user restriction level or available when a user hits rep level of 10? Then the user has invested a bit into the site before seeing the names of those who voted to close. There is still transparency, but you have to earn the privilege once you've got some skin in the game.
My reasoning for revisiting this is because we've had new users contact close voters off-site because they were upset about their question being closed. But before moving forward, I pulled some stats on how many users / posts would be impacted if we made this a privilege.
Across the network, I looked at questions closed in the past 90 days. In order to get a better overall picture of users impacted, I calculated the rep of the OP at the time question was posted and I checked to see how many OPs commented directly to a user who voted to close.
# Posts # Users # Users Commenting To Close Voters OP's Rep Range % Comments to Close Voters Site Name
------- ------- ---------------------------------- -------------- -------------------------- ---------
3435 3062 512 < 5 14.91 Stack Overflow
4046 3670 575 5 - 10 14.21 Stack Overflow
2724 2487 400 10 - 15 14.68 Stack Overflow
43 39 5 < 5 11.63 Super User
53 49 8 5 - 10 15.09 Super User
21 18 4 10 - 15 19.05 Super User
44 42 6 < 5 13.64 Server Fault
41 37 8 5 - 10 19.51 Server Fault
29 25 5 10 - 15 17.24 Server Fault
1 1 0 5 - 10 0.00 Cooking
3 3 0 10 - 15 0.00 Cooking
1 1 0 < 5 0.00 Home Improvement
5 5 0 5 - 10 0.00 Home Improvement
6 6 2 < 5 33.33 Game Developers
17 12 2 5 - 10 11.76 Game Developers
13 10 2 10 - 15 15.38 Game Developers
11 11 3 < 5 27.27 Gaming
25 25 3 5 - 10 12.00 Gaming
9 9 1 10 - 15 11.11 Gaming
185 173 16 < 5 8.65 Mathematics
377 323 45 5 - 10 11.94 Mathematics
243 222 14 10 - 15 5.76 Mathematics
3 2 1 < 5 33.33 Photography
2 2 1 5 - 10 50.00 Photography
1 1 0 10 - 15 0.00 Photography
22 17 6 < 5 27.27 Statistical Analysis
45 36 6 5 - 10 13.33 Statistical Analysis
13 10 2 10 - 15 15.38 Statistical Analysis
3 3 0 5 - 10 0.00 Web Apps
3 3 0 10 - 15 0.00 Web Apps
1 1 0 < 5 0.00 Webmasters
13 12 4 5 - 10 30.77 Webmasters
9 8 0 10 - 15 0.00 Webmasters
3 2 0 < 5 0.00 Personal Finance and Money
1 1 0 5 - 10 0.00 Personal Finance and Money
1 1 0 10 - 15 0.00 Personal Finance and Money
2 2 0 < 5 0.00 Role-playing Games
6 5 1 5 - 10 16.67 Role-playing Games
6 5 1 < 5 16.67 TeX - LaTeX
23 20 7 5 - 10 30.43 TeX - LaTeX
22 20 3 10 - 15 13.64 TeX - LaTeX
61 53 17 < 5 27.87 Ubuntu
82 76 22 5 - 10 26.83 Ubuntu
40 37 7 10 - 15 17.50 Ubuntu
26 20 2 < 5 7.69 WordPress
22 19 3 5 - 10 13.64 WordPress
8 7 2 10 - 15 25.00 WordPress
1 1 0 < 5 0.00 Bicycles
21 21 7 < 5 33.33 Programmers
6 5 2 5 - 10 33.33 Programmers
12 11 3 10 - 15 25.00 Programmers
13 11 1 < 5 7.69 IT Security
25 22 4 5 - 10 16.00 IT Security
9 8 0 10 - 15 0.00 IT Security
33 29 4 < 5 12.12 Electronics and Robotics
44 42 8 5 - 10 18.18 Electronics and Robotics
15 15 3 10 - 15 20.00 Electronics and Robotics
3 3 0 < 5 0.00 Graphic Design
9 8 2 5 - 10 22.22 Graphic Design
2 2 0 10 - 15 0.00 Graphic Design
5 5 0 < 5 0.00 Database Administrators
15 15 5 5 - 10 33.33 Database Administrators
15 14 4 10 - 15 26.67 Database Administrators
4 4 1 < 5 25.00 Science Fiction
4 4 0 5 - 10 0.00 Science Fiction
6 6 0 10 - 15 0.00 Science Fiction
6 6 1 < 5 16.67 Code Review
8 8 1 5 - 10 12.50 Code Review
10 10 3 10 - 15 30.00 Code Review
4 4 1 10 - 15 25.00 Code Golf
1 1 0 < 5 0.00 Quantitative Finance
1 1 0 5 - 10 0.00 Quantitative Finance
2 2 0 10 - 15 0.00 Quantitative Finance
1 1 0 < 5 0.00 Project Management
1 1 0 5 - 10 0.00 Skeptics
19 14 2 < 5 10.53 Drupal Answers
32 23 5 5 - 10 15.63 Drupal Answers
32 22 4 10 - 15 12.50 Drupal Answers
1 1 0 5 - 10 0.00 Fitness and Nutrition
1 1 0 < 5 0.00 Motor Vehicle Maintenance and Repair
5 4 0 < 5 0.00 SharePoint
10 10 0 5 - 10 0.00 SharePoint
10 10 0 10 - 15 0.00 SharePoint
4 4 1 < 5 25.00 Musical Practice and Performance
2 2 0 5 - 10 0.00 Musical Practice and Performance
1 1 0 10 - 15 0.00 Musical Practice and Performance
1 1 0 < 5 0.00 Software Quality Assurance and Testing
3 3 0 5 - 10 0.00 Software Quality Assurance and Testing
7 5 1 < 5 14.29 Jewish Life and Learning
7 5 1 5 - 10 14.29 Jewish Life and Learning
4 3 1 10 - 15 25.00 Jewish Life and Learning
5 4 1 5 - 10 20.00 Astronomy
2 2 0 10 - 15 0.00 Astronomy
3 3 0 < 5 0.00 German Language and Usage
2 2 0 5 - 10 0.00 German Language and Usage
1 1 0 10 - 15 0.00 German Language and Usage
1 1 0 5 - 10 0.00 Gardening and Landscaping
1 1 0 < 5 0.00 Travel
3 3 2 5 - 10 66.67 Travel
5 5 0 10 - 15 0.00 Travel
4 3 2 < 5 50.00 Cryptography
12 11 0 5 - 10 0.00 Cryptography
9 7 0 10 - 15 0.00 Cryptography
2 2 1 < 5 50.00 Signal Processing
6 5 0 5 - 10 0.00 Signal Processing
1 1 0 10 - 15 0.00 Signal Processing
4 4 1 < 5 25.00 Christianity
5 5 1 5 - 10 20.00 Christianity
4 4 3 10 - 15 75.00 Christianity
2 1 0 < 5 0.00 Economics
4 4 1 10 - 15 25.00 Economics
1 1 0 5 - 10 0.00 LEGO®
1 1 0 < 5 0.00 Movies
5 5 1 5 - 10 20.00 Movies
2 1 0 < 5 0.00 Chinese Language and Usage
1 1 0 5 - 10 0.00 Chinese Language and Usage
8 6 3 < 5 37.50 Biology
12 11 3 5 - 10 25.00 Biology
8 7 3 10 - 15 37.50 Biology
1 1 0 5 - 10 0.00 The Great Outdoors
1 1 0 5 - 10 0.00 Martial Arts
2 1 1 5 - 10 50.00 Sports
3 3 0 < 5 0.00 Academia
3 3 0 5 - 10 0.00 Academia
4 4 1 10 - 15 25.00 Academia
8 8 4 < 5 50.00 Computer Science
5 5 2 5 - 10 40.00 Computer Science
8 8 1 10 - 15 12.50 Computer Science
2 2 1 < 5 50.00 The Workplace
5 4 0 5 - 10 0.00 The Workplace
4 4 1 10 - 15 25.00 The Workplace
1 1 0 10 - 15 0.00 Windows Phone
17 17 2 < 5 11.76 Chemistry
31 25 8 5 - 10 25.81 Chemistry
10 9 2 10 - 15 20.00 Chemistry
3 3 0 < 5 0.00 Raspberry Pi
9 9 1 5 - 10 11.11 Raspberry Pi
4 4 1 10 - 15 25.00 Raspberry Pi
1 1 0 10 - 15 0.00 Russian Language and Usage
5 3 1 < 5 20.00 Islam
7 5 1 5 - 10 14.29 Islam
3 3 0 10 - 15 0.00 Islam
2 2 1 5 - 10 50.00 User Experience
3 2 1 10 - 15 33.33 User Experience
4 1 1 < 5 25.00 Robotics
2 2 0 5 - 10 0.00 Robotics
1 1 0 10 - 15 0.00 Robotics
4 3 0 5 - 10 0.00 Politics
1 1 0 10 - 15 0.00 Politics
11 8 1 < 5 9.09 Anime and Manga
8 7 0 5 - 10 0.00 Anime and Manga
5 4 0 10 - 15 0.00 Anime and Manga
14 13 4 < 5 28.57 Magento
43 35 5 5 - 10 11.63 Magento
22 21 4 10 - 15 18.18 Magento
2 1 0 5 - 10 0.00 Sustainable Living
3 3 0 < 5 0.00 Blender Stack Exchange
3 3 0 5 - 10 0.00 Blender Stack Exchange
11 10 3 10 - 15 27.27 Blender Stack Exchange
13 11 1 < 5 7.69 MathOverflow
17 14 4 5 - 10 23.53 MathOverflow
11 9 3 10 - 15 27.27 MathOverflow
2 2 0 < 5 0.00 Space Exploration Stack Exchange
2 2 1 5 - 10 50.00 Space Exploration Stack Exchange
2 2 0 10 - 15 0.00 Space Exploration Stack Exchange
1 1 0 < 5 0.00 Tor Stack Exchange
4 3 0 5 - 10 0.00 Tor Stack Exchange
5 3 1 5 - 10 20.00 Software Recommendations Stack Exchange
1 1 0 10 - 15 0.00 Software Recommendations Stack Exchange
1 1 0 < 5 0.00 Expatriates Stack Exchange
1 1 0 10 - 15 0.00 Mathematics Educators Stack Exchange
1 1 0 5 - 10 0.00 Data Science Stack Exchange
3 3 0 10 - 15 0.00 Data Science Stack Exchange
4 3 2 < 5 50.00 Puzzling Stack Exchange
4 4 0 5 - 10 0.00 Puzzling Stack Exchange
3 3 2 10 - 15 66.67 Puzzling Stack Exchange
2 2 1 10 - 15 50.00 Craft CMS Stack Exchange
1 1 0 < 5 0.00 Hinduism Stack Exchange
7 5 1 5 - 10 14.29 Hinduism Stack Exchange
3 2 0 10 - 15 0.00 Hinduism Stack Exchange
2 2 0 < 5 0.00 Worldbuilding Stack Exchange
8 7 1 5 - 10 12.50 Worldbuilding Stack Exchange
5 4 1 10 - 15 20.00 Worldbuilding Stack Exchange
2 2 1 < 5 50.00 Engineering Stack Exchange
2 2 0 5 - 10 0.00 Engineering Stack Exchange
5 4 1 10 - 15 20.00 Engineering Stack Exchange
5 5 1 5 - 10 20.00 elementary OS Stack Exchange
2 2 1 10 - 15 50.00 elementary OS Stack Exchange
2 2 1 < 5 50.00 Hardware Recommendations Stack Exchange
2 2 1 10 - 15 50.00 Hardware Recommendations Stack Exchange
Since I've limited the check to users who directly commented at a close voter, either user @username or left a comment with the username in the text of it, it's possible I'm missing some users who commented. Overall the percentages of users impacted is low so the question is, is this something that is worth it? Should the names of close voters only be shown once you've earned the privilege or should it remain completely transparent no matter what the rep level of the user is?
Additional stats as requested by Jon. I've limited the data to the posts where the OP has attempted to comment to a user who has not edited or commented on the post - basically, they've tried to comment to a close voter who didn't edit or comment - these users would not get a notification. This rarely happens, I've only included stats where there were users who tried to close directly to close voters.
# Posts # Users # Users Commenting To Close Voters OP's Rep Range % Comments to Close Voters Site Name
------- ------- ---------------------------------- -------------- -------------------------- ---------
2710 2463 5 < 5 0.18 Stack Overflow
3156 2920 5 5 - 10 0.16 Stack Overflow
2076 1945 1 10 - 15 0.05 Stack Overflow
7 6 1 10 - 15 14.29 WordPress
6 5 1 5 - 10 16.67 Christianity
I'm still thinking about it but it's definitely something I'm considering adding to the new user restriction privilege. Either way, I'll gather some additional stats before making a decision.