They said its gonna rival the production of FFXV like I said in my first post.

Sigh, link wars

https://www.unrealengine.com/blog/playstation-4-and-xbox-one-now-supported

https://www.unrealengine.com/custom-licensing

No mention of wii u on official site even with "wii u site:https://www.unrealengine.com/"

Which again says nothing about graphical fidelity and how much a game will push a console. Production costs <=> how many people are getting money + how much money those people are getting. Otherwise, KH3 will be a more demanding game than something like say The Witcher 3. Which obviously isn't going to happen. 

Because Epic personally isn't supporting Unreal Engine 4 on the Wii U does not mean other developers can't bring a game that uses Unreal Engine 4 to the platform, which is what the vice president Mark Rein was saying. Posting a link that only mentions official support from Epic says nothing to support your claim that Unreal Engine 4 cannot be used on the Wii U. Here's another source, by the way. 

http://www.engadget.com/2013/03/29/mark-rein-interview-gdc-2013/

"If someone wants to take Unreal Engine 4 and ship a game on Wii U, they can! If they wanna ship an Unreal Engine 4 game on Xbox 360, they could make it happen." While that game might not look as pretty as it would on a "true" next-gen console, the new engine is scalable to a variety of platforms, including mobile."

Ofc the correlation isn't 1:1 there's always other factors at play, but there is a correlation between the amount of money developers put into a game and its graphics.  If your gonna completely disregard that to push your agenda then there's no point in continuing this.

I never said there isn't a correlation, just that your assumption is baseless. There is no reason to believe that KH3 and FFXV will equally push the PS4, and that if the latter cannot be scaled for a less powerful platform the previous also cannot. Especially in today's age of very scalable games. Both games have different art-styles, different world sizes, and likely many other different features. Production values tell us nothing about how much a system will be pushed to its limits, other than the developer/publishers have the potential to. 

So we both agree that the Wii U isnt "officially supported" at least, considering the Ouya, Android and iOS all have entries on the Unreal site and blog. About KH3, I guess only time will tell but I highly doubt it.

Sure, but we don't agree that this means the game can't come to Wii U. It most certainly can. It just means the developer would have a little bit more work to do and no support from Epic. 

How can my assumption be baseless if there is a correlation.  If there is some sort of correlation then that automatically means my assumption has some merit behind it, I mentioned those other factors.  Anyway I specifically said they would need to downgrade the game on Wii U.

The Wii U can handle this game. Xenoblade Chronicles X looks way more demanding than KH3 tbh. Also the new Zelda looks about as demanding (if not a little less demanding) as kingdom hearts 3 IMO. Even if the Wii U can't run KH3, the graphics could be lowered/