The actor who originated the role told the Hollywood Reporter, "I'm delighted that there's a gay character. Unfortunately, it's a twisting of Gene's creation, to which he put in so much thought. I think it's really unfortunate."
Cho called Takei to tell him about the move, and Takei tried to explain his misgivings. "I told him, 'Be imaginative and create a character who has a history of being gay, rather than Sulu, who had been straight all this time, suddenly being revealed as being closeted.'"
While Takei's timeline doesn't work out -- Beyond is in an alternate universe and a prequel -- his point may be that Sulu has existed in the public consciousness for so long that having him "come out" in this chronologically late movie seems like he was closeted before.
Takei also told the Hollywood Reporter that he said a similar thing to director Justin Lin, arguing that the best way to honour the 50th anniversary year of Star Trek was to create a brand new character, rather than changing an existing one. After his exchange with Lin, he was left "feeling that that was going to happen".
A feeling that got even stronger when he got a letter from Simon Pegg, the writer of the film, "praising me for my advocacy for the LGBT movement and for my pride in Star Trek." It was only when Cho asked what he should do when he was asked about Sulu being gay that Takei realised no change had been made.
"I really tried to work with these people when at long last the issue of gay equality was going to be addressed," Takei added. "I thought after that conversation with Justin that was going to happen. Months later, when I got that email from Simon Pegg, I was kind of confused. He thinks I'm a great guy? Wonderful. But what was the point of that letter? I interpreted that as my words having been heard."
Honestly, the weirdest part of this story is that it was announced that this was in honour of Takei, who desperately didn't want it. It's a weird way to give a nod to one of the original cast members.