I dunno, feels like he wanted to make something that can lead into a sequel potential. I mean how many times did we see Hype Chan? Twice before she actually got a real introduction? But back in Solo Remix he probably just made her to tease everyone without actually thinking of a real plot until later. ( not a bad thing though, at least for me. )
It's kinda the same thing to other KH Final Mixes. I mean some people agree KHII should've been the real end, much like how OG TWEWY could've ended, but KH II Final Mix happened to link Birth By Sleep with a secret ending, and Solo Remix teasing hype chan as a secret ending. And then KH3's Yozora and 104 secret ending.
It's probably a reminder for him because it feels like Kingdom Hearts will be abandonded for a few years to focus on other games, much like how they abandonded TWEWY.
That said, him saying it's not connected just makes me think he still hasn't come up with anything yet, oh who knows that 104 may not be connected to first TWEWY or Neo, but the future events after Neo. Maybe KH3's sequel and NeoTWEWY's sequel is going to be one game, or it might be a Dissidia sequel overall where not all Final Fantasy characters but entirely Square Enix characters are gathered. Or Verum Rex IS the sequel and TWEWY and KH characters are just supporting characters like what they did to FF characters in KH, they exist but as entirely different beings, but TWEWY in DDD would still be the basis.
Welp, cast the firagas and i-flares on me now, KH and TWEWY fans.