To understand the game's evolution, one must first understand the file structure used on the Switch. The term (Nintendo Submission Package) refers to the file format used for digital games on the Nintendo eShop. Unlike the cartridge format, which can be restrictive regarding read speeds, the NSP format installs the game directly to the Switch’s internal storage or SD card.
The article you're likely talking about mentions that Mortal Kombat 11 on the Nintendo Switch has received a new update, which includes: mortal kombat 11 switch nsp update dlc better