I'm pretty sure it's a bug, but it may be caused by a new policy...
Adding Title/Description/Tags of videos with copyrighted material AFTER monetization has been approved is a known way to slip through the review process. Having another review every time someone changes these settings might be an easy way to take care of this, but keeping the videos under review for days and days and without end can't really be on purpose, and it would be very sloppy executed if the re-review only get's triggered on one of the multiple ways to edit a video, which makes my caused by a new policy theory rather unlikely. Usually the YT code monkeys aren't THAT stupid..[DOUBLEPOST=1370931957,1370931796][/DOUBLEPOST]
What's bugging me about this hope is that I haven't really seen anyone from YouTube/Google's side acknowledge the issue and it's not on their known issues page either...