I think MH is in a very strange place right now.
It was huge only in Japan for quite a while, where basically every new game added a few tweaks to mechanics and called it a day, then you had the off-year expansions that were basically the same game with added content sold for the same price as a new game.
But this worked because the MH fan base was very dedicated to the series, and the gameplay itself was quite niche.
Capcom finally really broke out with MH: World onto a worldwide hit, by heavily modifying the mechanics and gameplay to appeal to general consumers, forgoing a lot of the niche elements.
It's an amazing success, but I don't think the new larger fan base of general consumers will go for the same business model MH has used that worked for the dedicated fans, a new game every year or so with barely changed gameplay.
Iceborne seems to have done away with the off-year expansion edition and replaced it with DLC instead, which is a step forward, but even then, I think it will take more than that to avoid franchise fatigue that will eventually settle in unless the status quo is shook up a bit more.