The author's main motivation is probably the cool name "Nintendo Switch Switch" but a bridge is not a switch, so it should be called a "Nintendo Switch Bridge".
Being a little pedandic here aren't we? For all intents and purposes a bridge is basically a switch with two ports. At the end of the day this is running on a Linux kernel so it can basically be any networking device you want it to be, even a router.
No, even a two-port bridge is smarter than physical extension/repeater. I.e. the bridge will not forward ethernet frames to the other port if the destination if assumed to be in the originating network segment.