You're impatient.
This is the current status:
The Stack Overflow database restore started at 6:30:44. It takes roughly 6 hours for this to finish. So it is either done in the next 6 to 8 hours, or it is stuck.
Allow for another hour or so and then I'll close vote this as no longer reproduceable.
Note that your conclusion that it could have been synced until 05:09 (UTC) based on the Max(creation_date) is not accurate. That date is the last post that made it into production before the backup was started. After that moment the first evidence of timing is from the creation_date of the dtabase in SEDE. That is after the backup is finished and then it takes hours to populate the database.