Simon Pegg's already come forth to offer a response to Takei's vocalized concerns on the matter:
I have huge love and respect for George Takei, his heart, courage and humour are an inspiration. However, with regards to his thoughts on our Sulu, I must respectfully disagree with him.
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?
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.
I don't believe Gene Roddenberry's decision to make the prime timeline's Enterprise crew straight was an artistic one, more a necessity of the time. Trek rightly gets a lot of love for featuring the first interracial kiss on US television, but Plato's Stepchildren was the lowest rated episode ever.
The viewing audience weren't open minded enough at the time and it must have forced Roddenberry to modulate his innovation. His mantra was always 'infinite diversity in infinite combinations'. If he could have explored Sulu's sexuality with George, he no doubt would have. Roddenberry was a visionary and a pioneer but we choose our battles carefully.