As an homage to George Takei, the writers for the new Star Trek movie decided to make Sulu openly gay in the upcoming film, which would be a lovely tribute, except for the fact that Takei totally hates the idea. Takei played Hikaru Sulu in the original Star Trek TV series and in the early films, and despite being out and proud himself, told The Hollywood Reporter that he found the news of Sulu's sexuality to be "really unfortunate."
Takei, who is a vocal advocate for gay rights, gives many reasons as to why he thinks Sulu should remain straight, including that he thinks making a change like this would be disrespectful to the character that Gene Roddenberry created (woof, if that is the case, he probably has some strong opinions on the new Star Trek movies as in general). He 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." Although Takei urged the film's director Justin Lin to keep Sulu's heterosexual identity, production decided to move forward with making him gay. Takei noted:
This movie is going to be coming out on the 50th anniversary of Star Trek, the 50th anniversary of paying tribute to Gene Roddenberry, the man whose vision it was carried us through half a century. Honor him and create a new character. I urged them. He left me feeling that that was going to happen.
Another reason why Takei disapproves of decision is because of the implication that Sulu had been in the closet up until revealing his sexuality, something Takei suffered with in his personal life for over 40 years in the industry (he came out publicly in 2005). Here is more of what Takei told Lin:
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.

Simon Pegg, who co-wrote and starred in the latest Star Trek movie (and is also that guy from Shaun of the Dead), disagrees with Takei.

In a statement, he told The Guardian:
He’s right, it is unfortunate, it’s unfortunate that the screen version of the most inclusive, tolerant universe in science fiction hasn’t featured an LGBT character until now. We could have introduced a new gay character, but he or she would have been primarily defined by their sexuality, seen as the ‘gay character’, rather than simply for who they are, and isn’t that tokenism?
He closed his statement by adding:
Justin Lin, Doug Jung and I loved the idea of it being someone we already knew because the audience have a pre-existing opinion of that character as a human being, unaffected by any prejudice. Their sexual orientation is just one of many personal aspects, not the defining characteristic. Also, the audience would infer that there has been an LGBT presence in the Trek Universe from the beginning (at least in the Kelvin timeline), that a gay hero isn’t something new or strange. It’s also important to note that at no point do we suggest that our Sulu was ever closeted, why would he need to be? It’s just hasn’t come up before.
Wellllll, it may have come up before, actually. Takei does note that although Sulu never had a love interest on the show or in the original movies, there was an instance oh him having a one night stand with a woman in the 1995 Star Trek novel The Captain's Daughter, which resulted in Sulu's daughter, Demora, being conceived.
Although it is laudable that the current Star Trek team is trying to "boldly go where no man has gone before" by introducing a gay character, it is obvious that the decision has caused a rift between former and existing Star Trek stars. Who knew that there could be so much debate over LGBTQ+ stuff even in a galaxy far, far away (YES, I KNOW THAT IS STAR WARS. DON'T COME FOR ME, NERDS.)