Pretty sure Prime 4 will be made from the ground up for Switch 1 and will be ported to Switch 2 with only bumps in resolution, kinda like how BOTW was between Wii U & Switch. I doubt that Retro been working on this game as a Switch 2 game first when they started development in 2019 when the Switch was only 2 years old and having promised this game to come to Switch.