While the US and Australia had to contend with a digital release, or cases with a download code, or looks like the EU will be getting the game on cartridge.
Amazon UK has a new listing for Mortal Kombat 11 Ultimate (Nintendo Switch) and mentions that the box contains a Nintendo Switch cartridge.
This edition will include Mortal Kombat 11, Kombat Pack 1, Aftermath Expansion, and Kombat Pack 2. Release is scheduled for the 17th of November 2020.
Source: Nintendo Life