Really? I don't know, I used to love anime some years ago, but nowadays I'm just sticking to a couple of mangas (basically One Piece), although I'm not as excited about them as I used to be.
I say that because... well, he's a prince lol. So him having a fianceé already wouldn't be shocking, and I think it would give lots of possibilities to the story and the characters' relationships.
That said, I don't want XV to have a love triangle (I'm assuming lots of things, sure, Stella is likely just a friend/enemy), or at least not a prominent one. If they go there, I want at least some subtlety, and it being more of a side thing.