Yesterday I noticed an large amount of playframework questions hit the first page of the active tab. They all got edited by the same user.
Anyways, the play-mvc tag is useless and redundant. Play is already a MVC framework and there is no thing called "play-mvc". Most tagged questions aren't even about MVC in any particular.
The play-mvc wiki is just a reworded version of the playframework wiki and provides no additional information. Again, I think this was done just so the user could get the tag-editor badge.