[Enchilada645]

I feel like your theory holds weight considering that the Uchusen (the book that gives us close up angles of the Rider suits in good quality) did give a remark on Buffa Musou from what one person mentioned about...

"Did Buffa lose this power?"

Which implies that it clearly isn't gone and there's more going on. Might even factor into how Buffa still had Command despite Grand End occurring (I'm not sure they'll explain that but hey, weirder things have happened). It makes it potentially reemerging and becoming Maou in the next few episodes very likely, especially with a bunch of antagonistic Riders coming back.