At least with regards to the storyline, it seems like most core fans of the franchise are happy with the decision of the developers and don’t object to having to buy another game in order to dig deeper into the plot.
Whether or not they will be so happy with the final result is a different story of course, and we shouldn’t forget that we’re going to hear the opinions of other people at that time as well, not just the most dedicated fans of the franchise.
It actually seems like Disney are trying to bring some new people to the series with this release, as talks about the game somewhat imply that it’s designed with improved accessibility and intuitiveness in mind.
This might not be a good thing in the grand scheme of things, according to some fans. The potential problem is that it could make the game feel too dumbed down and straightforward, something which old-school fans are definitely not going to want to see.
But it’s too early for predictions like that. Right now, the important thing is to focus on the official talks about the game, and remember that a lot is probably kept unsaid. It’s just the way things tend to be handled when it comes to “Kingdom Hearts”, and fans of the franchise should be more or less used to the idea at this point.