Games take their time to develop. There's only so much discussion to be had. The main story is complete. Things set up from KH1 are concluded in KH3 for the most part. Going forward is likewise hard to discuss given the topic at hand is typically esoteric as Nomura is want to do.
KH3 + ReMind + Melody of Memories spoilers (click to see content) There was plenty to talk about between prior games because they were steadily coming out fast enough and left freaking out of left field clues all over the place seemingly not connected to anything. Like random bonus cutscens of Xemnas having personal time locked up in a basement talking to a suit of armor. Or all the pre-rendered post-credit cutscenes that without context seemed to be completely unrelated. By 2005, you could have been caught up on every feesable scrap of information there was and this would still slap you upside the head with no idea how to explain its relation to KH going forward. VIDEO So in short, it's not dead. Just finished it intended run. There were mysteries to solve that had actual answers. They're answered now. Wait some time before the next cycle.