Why would you retool a game when the current formula work just right? That doesn't make sense. Even more so in recent comment where Capcom said they met difficulty with developing modern games due to rising necessary resources to pull.
Because the current formula never really took off on consoles, and really took off on a format where the mission-based quick structure gelled with a portable/go-anywhere system in the PSP. That's since continued and the system has evolved, but in a lot of ways it still heavily leverages a bite-sized structure that's a lot like the strikes in Destiny.
The west also picked up on this formula on the 3DS, but other brands of the type of structure have never found success in the west in this or even previous gens, really. We need only look at how other similar brands have tried to shake off the formula of MH for something more open world. You could even consider Dark Souls in a similar vein and its not "mission based" its a contiguous world with "boss hunts".
The west/console demographic would have more easily greased cogs with something open-world/open-world~ish with a more streamlined structure/combat. Look at Horizon, its a lot like what I'd expect for a MH on consoles.
Weighty combat is also been a pretty hit or miss proposition. Dark Souls, I think, really only ever got away with it in the west because of the notion of "git gud" and the lexicon that evolved around the series and its combat.
