Nintendo is notoriously protective of its Intellectual Property (IP). Downloading a ROM for a game you do not own a physical or digital license for is a violation of copyright law. The Internet Archive operates in a legal gray area; while they claim preservation rights, Nintendo has historically issued DMCA takedowns for their content.
The Internet Archive serves as a massive repository for digital history. While primarily known for books and web pages, it also hosts various gaming-related files: mario kart 8 deluxe rom internet archive updated
Dumping your own MK8D cartridge to a PC for personal use with an emulator is argued as fair use in some jurisdictions—but redistributing that dump on the Internet Archive is undeniably illegal. The Internet Archive serves as a massive repository
For legal owners, the Nintendo Support Page explains that updates download automatically when connected to the internet. while they claim preservation rights