Nintendo Europe has confirmed today that the Version 1.1.0 update for Animal Crossing: New Horizons will be available to consumers on Thursday. It will go live at 2am CET on Thursday, 19th March. If you’ve preloaded the game via the Nintendo Switch eShop it will start downloading automatically ready for you to play on Friday when the game launches.
The Ver 1.1.0 update for Animal Crossing: New Horizons will be available ahead of launch, starting at 2am CET on 19/03. If you've preloaded the game from #eShop, the update should start downloading automatically. #ACNH
— Nintendo of Europe (@NintendoEurope) March 17, 2020
Long shot but…maybe it’s an amiibo update to flush them out more?
I think its the update that brings the easter event to the game. They said it will be added when the game launches, so that would make sense.