Wow, all that time and money wasted.
Now we will be stuck with Chromatic Aberration galore and silly UE4 problems and next to 0 chance of any kind of proper anti aliasing that doesn't induce ghosting, smearing and obscene blur. (Luminous has MSAA support which means SGSSAA is potentially possible. UE4 doesn't give a shit about that kind of stuff. Though it's certainly possible it could've improved lately. I'm not a UE4 subscriber, but every demo and game i've seen/played myself with my own eyes with it so far. It's not been great)
The problem with Unreal is, that too many stick to what is given to them. That's been UE's biggest problem since day 1. (Especially when a new version of the engine arrives)
Given though that Luminous is tailored to PBL and all that jazz, I suppose I could see that a problem with KH3, but I mean FFS, what they showed off didn't seem to look wrong in any way and looked really unique to boot.