It's just going to be a blurry sub 20fps mess. The switch had serious problems with playing doom, I mean its LOWEST was 612p 20fps and that's just for a linear shooter.
MHW is an open world game with ridiculous AI monsters, it has a huge open world too. I doubt if the game would even be playable, it will no doubt look severely downgraded compared to the console counterparts soooo I'd say good luck but I'd advise them to not even bother trying.