And in the very same game we get a secret ending that suggests a game taking place in the past because it references Xehanort's past/memories.& saw that post-credits tease.
it was always Nomura's intention to expand KH's lore before getting into KH3.
But back to the topic, I'm optimistic and think that they'll reveal the next title in 2022. If it's using KH3's engine, then they already have existing assets, meaning that development shouldn't take as long.