Well, I think the whole conception of when something needs to release has been changing these days. Movies have found that it doesn't need to release in the "summer" time period to sell billions. Games have also been releasing more and more out of their 'typical' window.

But I would say late Jan, early Feb is being optimistic for Kingdom Hearts 3. I'm expecting later. I was watching some predicitons for E3 and a group brought up Kingdom Hearts at E3 and its release. They then talked about how they got a hands on time with the game at some place and got to talk to devs and so on. The impression they got at that was that the game is not ready yet, so they didn't believe it would be a 2018 game. Thus in the same thinking, it being like month 1 of 2019 seems unlikely. Toss that onto it being  SE game as well, and I woudl not expect this until like Spring 2019. 

It just doesn't make sense. Imagine a console released by Nintendo which was exactly like a PS4 Pro. Same online, same internals, same basic media... basic controller. Now imagine Nintendo releasing BOTW, Metroid Prime 4, Odyssey... and then throw in COD, Madden, GTA 6, Battlefield... all those really massive casual franchises. Who the hell would be able to compete? Sony? They have great exclusives, sure. But if Nintendo is getting the same third party support and their versions are just as good, Nintendo is going to win that fight because in the end, their exclusives sell better and are in more demand. GOW is great. Bloodborne is great. But they don't sell anything like MK or Pokemon. 

There's literally no evidence of Nintendo ever losing under this strategy and, if they ever tried again, trust me, Microsoft and Sony would shit the bed secretly because they have used Nintendo's gimped hardware and different controller strategy to their advance for years. They have lived off the fact that by default, Nintendo won't be getting the best third party games. If Nintendo threw down the gauntlet and said, ok... no more freebies for you guys, imo, it could be game over for their dominance.

Until Nintendo finally decides to make a console that is as powerful as their competitors and with a similar architecture (internals, storage media etc.), this is going to happen. It's been going on since N64.

GameCube has twice the clock speed of the PS2. 486Mhz compared to the PS2's 200Mhz.

And there is no point to make a console as "powerful" as PS4 and XO, since Nintendo has been the only company that actually profits on every system, game, and accessory they sell.

It's bad enough that PS4 and XO are literally the same exact system with different names. Do we really need three systems that are all the same? Nintendo answered that in 2006. The answer was no.