The popular narrative seems to be that Yuzu had something to do and/or profited in some way from the Zelda Tears of the Kingdom leak, which isn't true. The Patreon-only Early Access builds could not play the game any more than the public Nightly builds could. Both versions needed an unofficial game patch for the game to launch, a patch which the Yuzu developers had nothing to do with. Yuzu developers also did not implement or work on any bug fixes involving the game before its official release. Perhaps you were alluding to something else, though.
I thought that there was also speculation of people sharing ROMs directly on Discord, with the Yuzu admins being pretty ambivalent about the whole thing?
I only followed the story peripherally, so it's possible I'm wrong.
I was there, this is true.
I thought they were sharing Nintendo encryption keys that are "technically" supposed to be from the Switch you're emulating. People were using Yuzu to turn their Steamdeck into a Switch and using Yuzu's private discord to get the keys needed to do that.
It's the same reason other emulators ask you to bring your own BIOS file because that is proprietary.