It kinda sounds like you conjure up whatever you want, most of the things you said were never confirmed, shown or even talked about.
It absolutely is, its just fun to talk about.
For instance, im 99% certain that Cyberconnect 2 is involved
-They developed FF7 G-bike
-They are Nomura's "first choice" for outsourcing (Per kitase)
-CyberConnect2 CEO described one of their projects as "Open World" "Photo Realistic" "Worldwide appeal" "Console" "PS4". That doesn't describe your typical japanese game.
-They flat out said last year that they wanted to make the FF7 remake.
-They already use UE4
Im also 99% certain that UE4 is the engine.
-Square already has it licensed
-KH3 is using it
-Luminous isnt finished
-Cyberconnect2 is already familiar with UE4.
Why i think its an action RPG
-Nomura created KH3 and Versus
-He already said the characters wont just stand still and take turns attacking
-Cyberconnect2 is an action developer
Why i think its ditching the overworld for an open world
-Its not the 90's anymore
-Already stated they they arent just going to make the same game again.