Its not a huge mistake to go cross gen with this title. Its not going to matter that much and there's plenty of cross gen games on other platforms where the game was built more for the previous gen. They just built a brand new engine for the game and already used it on MP1 remastered. The fact that the engine works well on Switch 1 might very well be a benefit to Switch 2. The fact that before features and improvements are added to the title it wouldnt take that many resources away from Switch 2 is a benefit. It will make it alot easier for Nintendo to show off advanced features. It will probably have the resources left over to run at 4k using DLSS unlike 3rd party ports, it should be able to handle really good ray tracing ect. And with that art style its already going to look good. Its even going to look good on the original switch for cripes sakes. If you pair that with some nice 3rd party ports at launch, people will get a good showcase of what the system is capable of. Im thinking Resident Evil 4 Remake and Call of Duty ect.
I think its very reasonable to expect that the engine was designed with cross gen in mind.