romance between Grindelwald and Dumbledore?
Wonder if they'll do this or not. Really, they're in sort of a damned if they do, damned if they don't situation.
JKR has stated that Dumbledore felt that way, so it's canon. But she said it after the books ended, and it didn't play a part in the story. It can be argued that it did, but unstatedly.
If they don't do it, they'll offend gays who want inclusion. If they do, they'll offend One Million Uptight Moms.
If they don't, it'll feel ignored. If they do, it'll feel forced. Granted, this whole series is literally stretching a 100 page fictional textbook and acting as backstory filler, so there's that.