Okay, first of all, WTF? There's NO indication in the previous movies that Sulu has a wife or child. NONE.
So what?
Sulu was a glorified spear-carrier in TOS. TOS wasn't the soap opera later Trek was, it had no need to tell us what time Ensign no-name took a leak.
And furthermore, everyone knew George Takei is gay. Yes he only "came out" a few years ago, but everyone he worked with knew it for years. So why would they give him a daughter? Was it to taunt Takei, saying "ha, you'll never have one of these in real life!" How horrible if so.
Wow. That's three different levels of stupid.