Nintendo’s eShop for the Switch has not shut down, but physical cartridges degrade, and digital storefronts eventually close. Many archivers seek “Hyrule Warriors Definitive Edition ROM NSP” as a future-proof backup, especially because the game is no longer receiving new physical print runs.
The "m upd" (multi-update or latest update) refers to patches that refined the experience after its 2018 launch. Notable fixes and additions included: Gameplay Fixes
: Purchase item cards in Adventure Mode once they have been initially discovered. 3D Fairy Models
This version is titled "Definitive" because it includes all previously released paid DLC and updates from the prior console versions.
: Restores two-player split-screen co-op on a single console using individual Joy-Con controllers. Hyrule Warriors: Age of Calamity
When Hyrule Warriors: Definitive Edition launched on the Nintendo Switch in 2018, it wasn't just another port. It was the culmination of years of musou-style Zelda action, combining the base game of the Wii U original, the 3DS’s Legends content, and every piece of DLC ever released—plus new Breath of the Wild-inspired costumes. For fans, it represented the definitive (pun intended) way to experience Link, Zelda, and a sprawling cast cleaving through thousands of enemies.