The character of Sulu is very close to Takei’s heart. The fan film World Enough and Time (Highly recommended) stars Takei and solidly cements Sulu as heterosexual. While not canonical, Takei is very proud of this production and more than likely considers it part of his personal canon for the character. For the filmmakers to approach Takei for his input/blessing on something that they state is meant to honor him and then completely disregard his wishes is disrespectful.
That’s fair. I get where he’s coming from.
Personally I’ve never been crazy huge into Trek so I’ll admit to not knowing the canon inside and out. But nothing I’ve seen contradicts making Sulu gay. Unless I missed a part where Sulu made it clear he only had eyes for women, or unless the new film makes it clear he only has eyes for men, I still don’t see where the continuity issue is.
It’ll probably depend on how the new film handles it but I’m sure it’s not hard to believe that the timeline divergence could cause him to end up in a different relationship.
Not to mention the fact that this alternate timeline already strains credibility in many ways of actually being based on the original timeline anyway. I find it easier to enjoy if you just watch the films as straight up reboots. In that case there’s no problem at all.