I don’t see what’s wrong with it at all. I’m hard pressed to think of why it’s a problem in anyway. It literally isn’t at all.
As for the cynical side, from what I understand this is one of the screenwriter’s opinions that was brought up in an interview and it’s been blown into a big thing by media outlets. Disney hasn’t mentioned it so it’s not really a Beauty and the Beast or Star Trek Beyond situation where it’s a pandering marketing tactic and I’m not sure it’s even canon.
Who knows if there’s any sign of it in the movie but I will say if there isn’t, that’s lazy to say he is that then. In that case calling it pandering makes sense. Otherwise bullshit. Every time a story includes a non straight character, nerds complain loudly about “pandering.” Yet of course no one cries “pandering” when they’re straight. It’s bullshit and you’re part of the problem if you feed into that.
I know George Takei was upset, but it doesn’t mean Prime universe Sulu can’t still be straight. Showing a gay couple in Trek was long overdue. A big improvement over casually mentioning (but not onscreen) that a minor character in First Contact was gay and they end up the major redshirt in the movie.
Even if Takei was upset (which is totally fair for him to be), he’s not the arbiter of everything that can be done with that character, especially, as you mention, that it’s not even in the same universe.
I should clarify the reason I bring it up is they definitely overdid the hoopla on that one, considering how small it was in the film. Not that it needed to be bigger, but don’t go patting yourself on the back for a blink and you miss it moment. To Jon Kasdan’s credit, it just seems like someone asked him a question and he answered it. Would be interesting to hear Lawrence’s perspective considering he is one of the character’s creators - but again, that wouldn’t mean he should necessarily have the final judgement.