Oh yeah, those are all fair points. I guess I'll know after I finish birthright haha. You don't save after the credits, do you?Berret did get that glitch that said he married Niles. So, maybe if you married a male as a male on the Birthright path, it would cause the game to crash on the credits because Niles (the only male/male option that's supposed to be in the game) isn't on that path. Same thing would apply to marrying a female as a female on Conquest since Rhajat is a Hoshido character.
Also, I don't think Berret mentioned if he did any other same-sex pairings besides Corrin/Benny. If he didn't, there might just be a problem with the other characters since Corrin, Rhajat, and Niles are the only characters who are supposed to have same-sex supports in the game.