In one of his latest interviews, Nomura said that he's pretty "confident" about a 2018 release year for KH3. Well, guess what: I DON'T BELIEVE HIM. At least, not 100%. Here are 2 reasons why:
1) I'm on the team that believes KH3 will have 20 worlds (since he said KH3 will have more worlds than KH2). 20 = 7 lights + 13 darknesses. And if, again, IF this comes true, then let's count how many worlds we have so far (Confirmed worlds said by SE themselves or shown on screenshots, artworks, etc. I'm not going to consider probable/possible worlds here, like Frozen, for example):
1.1) Twilight Town;
1.2) Tangled (Rapunzel's world);
1.3) San Fransokyo (Big Hero 6 world);
1.4) Mount Olympus (Hercules world);
1.5) Toy Story world;
1.6) The Mysterious Tower or Symphony of Sorcery;
Do you guys see? Only 6 worlds out of the 20 ones have been revealed so far. And, I've read on this site that the next KH3 information/news will only come out at D23 Japan next year (which, actually, should happen THIS year). Even if he announces 1 world per month from D23 onward, there's no way he can show us all the 14 remaining worlds KH3 will have (like he said he would do: reveal all the worlds) before it launches (unless he reveals 2 worlds each month or something like that, but this is highly unlikely. He's never done that before and the chances are very slim he'll do that).
2) He is getting a little overconfident. I'm pretty sure Hajime Tabata and Nomura were also very confident they could release Final Fantasy XV and KH 2.8 FCP in September and December, respectively, and we all saw what happened, right? Who's to say this won't happen again? Delays happen all the time, don't they? Especially when SE is too afraid of the idea of FFXV competing with Persona 5 and then, what happens? Both games are delayed. And this delay affected 2.8's original release date, which was supposed to be December.
Well, this is it. I hope I'm 100% wrong, but, until the game launches, I won't trust Nomura 100%.