Been using GitHub for over a decade, only now realized that users could benefit from having an “undo merge” button for PRs. I think Gmail used to have that for sending emails as an experimental Gmail Lab feature (perhaps they still do). I believe it would make this platform even more indispensable when it comes to dealing with merges.
It may seem like a bad idea to some, but please keep in mind that one of the jobs interfaces have is not only be pretty, but also be accessible to everyone, and since we’re all human, our nature lets us make mistakes when we’re acting without thinking, e.g. when we’re tired or just not paying attention.