I don't know how I feel about this, to be honest. I mean, yes it's great Star Trek has finally made some efforts to acknowledge homosexuality, Sulu is not the character I would have chosen. George Takei has been insistent even after he publicly came out that he believes Sulu to be straight. Although I'm sure he's not complaining about this news, I still would have honoured his intention. And before anyone suggests "well he's straight in Prime, and gay in Abramsverse" does that even make sense? The presence of Demora kind of muddles the issue, I'm guessing she's adopted in the Abramsverse. What about the Prime Universe? Did Sulu and his (presumably) female partner adopt her there, too? I guess it's possible, or maybe we now assume Prime Sulu was gay too? I guess there's no reason based on what we saw in TOS and its movies that he can't be, and Takei's intent certainly isn't canon.
Whatever, I'm clearly overthinking this. Let's all just be glad we have our first gay main character in the Trek franchise after fifty years.