Delete room tags at the schedule first! (don't if you have a lot of data attached to them, like room finish info)
Wordy, punchy commentary followsyou just read what you need to know, if you want to be distracted read on...)
If you liberally apply room tags in a project and "someone" has the nerve to change things on you...you've no doubt been introduced to the room tags message dialog about, the room tag refers to blah blah blah.
Why oh why you say? Everytime you tag a "room" Revit knows about said room. If you've labeled the 1/8 plan and the enlarged plans and the area layout plans etc. You now have several tags identifying the room even after you delete just one...now you delete or move a wall and you just confused poor Revit who says, "But I thought this was supposed to be a room?"
My preferred strategy when faced with changes that mess with rooms...is to start at my room schedule and delete the rooms that I have to change there. Doing so kills ALL the tags (and data associated with) that refer to that room in one step. Now any changes to those spaces that were perfectly nice rooms till "someone" changed them aren't "known" to Revit anymore and you can edit freely without dialog "ell".
Keep in mind that doing so also wipes out any data that room acquired (like room finish schedule info), so it is NOT a good strategy to employ if the room must exist (and it's data) after changes take place with only a different look. You're better off being visited by dialog boxes then (you could delete the all tags by visiting all views...if only you could remember all the places you tagged it)