Yeah, it's easy to have a prequel character that doesn't show up in the original and have that make sense, but technology is much harder to explain away. You generally need some form of major societal collapse to explain why tech in a prequel isn't around anymore. So long as anyone knows how to make the tech, it will come back. Even someone just being aware that the tech existed can result in someone reinventing it.
This isn't too difficult to accomplish if the setting is before the information age to begin with, but it's much harder to justify if the internet or an equivalent is around. We lost the secret of how to make concrete for about a thousand years following the collapse of Rome. On the other hand, David Hahn built a nuclear reactor in his home with just books from the library. Those books are now available any time you want on that neat rectangle you keep in your pocket, and we know from experience that you can't really scrub anything from the internet, so they'll always be there so long as the internet still exists.
Somewhere out there on the Klingon portion (and probably the Romulan portion) of Trek's internet equivalent are detailed accounts of the USS Discovery, her crew, and her spore drive. The ship was operating completely in the open, after all. And since the Klingons never classified that info, it would be easily and readily available to anyone who can read Klingon or has access to a universal translator.