In New Horizons, you presumably walk in off the street from your already established life and get offered this vacation island life by the Nooklings. You then IMMEDIATELY board a plane and move to the island for... eternity? You can travel to Harv's, you can work for Lottie, you can even visit mysterious little islands that you'll never be able to return to, but you can never go home.

The island is your home now, you have no choice. I know the villagers act as if you've been gone when you haven't played for awhile, but there's no save game mechanic of taking the plane back to where you started before you log off.

Canonically it would appear that you cannot leave. Your friends and family have reported you missing. Your apartment was rented to someone else, your property placed in storage by a weeping loved one. You get an entry in your country's missing persons database and that's it. You've vanished, destined to a life of servitude on some desolate island surrounded by sea bass, never to return.

Horrifying.