After reading this change, I understand why it was made, and it's probably for the best. But this change confused me in a way that caused an edit of mine to be unfairly rejected. I think this new feature could be improved to prevent that confusion.
Here's how my problem came about: I wanted to retag a question. I looked for the old retag link – but it was gone! Fine, I thought, I'll just edit the question. And then I edited the tags in the question. But then I remembered the rule of editing “make substantial edits”. If I just change the tags, I thought, my edit won't be substantial enough and it will be rejected. I guess I have to change more things, to make my edit substantial. Weird – I wonder where the retag feature went. So I also changed one little thing in the question body in my edit to try to make it more substantial, and then I submitted my edit suggestion.
But after a few minutes, my edit suggestion was rejected. I'm not sure if it was because it was too insubstantial – my suggestion was “Rejected”, but a reviewer chose the Edit option to post it after editing the tags further. But it is at least possible that I would have had the edit straight-out rejected for being too minor. Either way, that edit increased my “rejected edits” statistic by one, which I did not deserve. If I had known the new method of retagging, I wouldn’t have also edited the body of the question, leading to the rejection. But the site failed to communicate to me the method of editing tags without the edit being reviewed.
To fix this, users should somehow be told that edits of only tags will happen instantly, unlike most edits. One way to do that would be to change the label of the “Save Edits” button, depending on what edits the user is making. As soon as the user edits something other than the tags, the button label could change to “Suggest Edits” or “Propose Edits”. Alternatively, we could just state in the “How to Tag” sidebar that “edits of only tags will automatically be accepted”. Or perhaps the tag-editing field could have a different background style from the rest of the page to subtly suggest that editing it will work differently.