I don't really know what you're trying to say with your post. I just want to not have to worry about reassigning the same room every time the mayor dies.
And I just want to not have to worry about reassigning the same room, squad, burrow every time the mason, carpenter and any other dies. Not only Mayor, not only room.
Make somthing like this:
1 Start fortress
2 Add any number of additional noble "titles". Like "Royal woodcutter", or "Food Hauler"
3 Assign dwarfs to this positions
4 Assign rooms, burrows, squads and any others things not only for common dwars, but to positions too.
So we need only screen to create "virtual" dwarfs an then add this dwarfs to game.
When we adds position of "The Greatest Mason Ever" we could assign bed or workshop for this title the same way as we do it for any casual Urist. And this virtual dwarfs could be nobles too, to make this feature not so easy to use.