30fps is a bit disappointing, but not entirely surprising. If it's a solid 30 I'll still pick it up (and it should be, given the variable resolution). Given that a variable resolution solution is already in there, ideally they'd give players the option to play at 60fps and take the extra resolution hit, but I guess they just don't want to put out a game running at such low res, even as an option. Alternatively it could get CPU limited by that point.
The decision to use an outside studio to handle the port is interesting. Most likely motivated by the fact that id's engine team have been so busy on Wolfenstein for the last few months. I wonder if id will properly integrate Switch support into the engine for Wolfenstein, though, as if Bethesda plan on using the engine for more projects in the future, and they also plan on continuing support for Switch (both of which seem likely), then it makes more sense to have it as a main build platform than relying on ad-hoc ports.