Actually, it's Nintendo that have the confirm (A) and cancel/back (B) in the oposit places. Playstation, Xbox and now Stadia have it where it "should" be.
I dont play on my Switch that often, 90% of my gaming is on my PS4 and Xbox, but when I do it always takes some time to get use to Nintendos button layout.
Although technically they have it the "right" way in Japan as circle means okay/good and X means bad/wrong so if you look at the PlayStation controller and play a Japanese import the buttons funtion/prompts will be reverse. My guess is western PS divisions thought pressing X for most things was just more comfortable.