MHW has a lot of granularity to its graphical options that could, in theory, make it an easy enough game to downport if they wanted to. However, and this is the crucial part, the UI would need a gigantic overhaul to be suitable for the Switch's screen and that wouldn't be an easy task with how much information the game throws at you that you need to pay attention to. The minimap in particular would be a nightmare to read if you were trying to parse out any local resources to gather.
That said, I strongly suspect that the MT Framework fork that World uses has zero compatibility with Switch because why would it from the team's perspective, so even on the face of there being plenty that can get tuned down to make porting easier, you still have the big issue of getting the engine to work on Switch in the first place. You really can't use the current MT Framework ports on the system as a guideline either, since they're much older iterations. Any potential new game for Switch would likely still be MT Framework, but perhaps even a whole new fork altogether to better suit the platform while incorporating some of the new design elements that World features, like the seamless zones.