FYI, they changed the default of 'git.addAICoAuthor' to 'chatAndAgent' afterwards: https://github.com/microsoft/vscode/pull/312880
So it was 'off' -> 'on' -> 'chatAndAgent'
This should be higher, as this dates from 5 days ago I wonder why OP didn't bother to mention this follow-up
Changed back or not, this demonstrates that they're either willing to make sweeping changes like this that hurt a massive number of users, or that they're incompetent to the point of not realising the impact of the first change. They'd have had to just blindly make the change, since the original PR was approved and merged within the same minute by the original author (no additional eyes, at least that we can see), or ignore user complaints and make it anyway. Both cases demonstrate terrible stewardship of VSCode.