Updating a game via NSP requires a matching update file. Because the Legacy Edition is discontinued, you will not find new feature updates for it. Nintendo Switch Edition - Minecraft Wiki
The actual final update for this specific edition is version 1.0.17 . minecraft nintendo switch edition nsp actual upd
The original Nintendo Switch Edition (the Legacy Console Edition developed by 4J Studios) is a separate game from the version currently sold on the eShop. Updating a game via NSP requires a matching update file