The problem is that Nintendo likes to play victim to piracy, surprising considering how their abandoned titles are kept alive by great folks who are only breathing new life into games that would otherwise be lost to time.
That's not true. Pikmin uses Hagi, which is Nintendo's own emulator. Nintendo never used an open-source emulator in a release product.
See this fellow confused guy's thread: https://gbatemp.net/threads/pikmin-1-2-use-dolphin-emulator....
https://www.nintendolife.com/news/2021/05/nintendo_accused_o...
There has been accusations that some "in house" emulators are also open source ones with superficial changes
They have also been found to use ROMs dumped by end users and posted on the normal ROM sites for their "play an old game" products.
The rom thing was only the same rom format. How are you going to tell if it's the same dumps or not? Roms are supposed to match 1:1, otherwise verification hashes projects like redump and no-intro wouldn't work.