I don't think so. There are lots of people who want to connect things like Playstation to display it on the iMac screen but there's no capability of doing that either. It's a waste of a screen in my opinion, and it would be very cool if you could do what you mentioned with the Switch. You can however use PS4 Remote Play to play a PS4 on a Mac over an Internet connection. So it's technically possible. I don't have a Switch and don't know if there is an app like that.