Sulu will be canonically, openly gay in Star Trek Beyond.George Takei is actually opposed to this
, for a few reasons. One is that he thinks creating a new character is better than altering an existing one; another is that he feels it contradicts the character as Roddenberry conceived him. A third is that he believes this retroactively implies that his version of Sulu was closeted.
There's something to be said for all of these points, and I respect Takei's opinion, but I don't know that I agree with it. First of all, there's not really much in the original series to establish Sulu's sexuality at all -- if the creator and actor both intended for him to be straight, then that's perfectly valid and Takei has a right to think that's the "true" interpretation, but I don't see it up there on the screen.
Second, it would probably be a good idea not to take the "these are the same characters, just younger" premise too seriously. How did Nero blowing up Captain Kirk's father make Sulu gay? The same way it made Khan white, and caused Uhura and Spock to date. For as much time as the first movie spent telling us that these are the same people, younger, in a timeline that was altered by a couple of major events, I think it's a lot more constructive and accurate to look at it as a reboot, as loosely-similar characters with the same names experiencing loosely-similar events to TOS.Pegg and Quinto repsectfully disagree
with Takei's interpretation.
And of course new characters and gay Sulu aren't mutually exclusive; I hope we'll see some LGBTQ characters on the new TV series. But if "just make a new character" were an option, this movie series wouldn't exist at all; its entire purpose is to capitalize on nostalgia by reusing the characters from TOS.