He insisted that even though he is gay, the Sulu he portrayed is straight.

"Unfortunately, it’s a twisting of Gene’s creation, to which he put in so much thought. I think it’s really unfortunate."

Takei was not into it, but I do feel like he was overselling just how much thought Roddenberry put into the side characters in Trek. Sulu didn't even get a given name until "The Voyage Home", a film Roddenberry had nothing to do with.

(In Generations, Sulu is married and has a daughter, Demora, who helmed the Enterprise-B.)

Demora is Sulu's daughter, but there's no mention that Sulu was married, or if he was that it was to a woman.

(and Cho himself is cool being a straight Korean playing a gay Japanese)

Funny you mention the character's nationality, considering that Roddenberry envisioned Sulu as some pan-Asian character on indeterminate nationality. Sulu is not a Japanese name, and Roddenberry chose to name the character after the Sulu sea of the coast of the Philippians.

Please don’t assume that I thought otherwise just because I didn’t explicitly mention every potentiality in that one post.

That was not my assumption. I just can't think of any reason to assume that Sulu is not bi or pan, given what we know about the various iterations of the character.