What you are referring to as Linux, is in fact, GNU/Linux, or as I've recently taken to calling it, GNU plus Linux. Linux is not an operating system unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX.
with the federated nature of the verse, do we need a name for a single contributing platforms users?.. maybe.
you have kids using only 'apps' who barely know what the lemmy platform does, because all they know is the app theyre using.... you could have magazines that have zero lemmy users contributing, because the content and its users are interacting from different, compatible fediverse platforms.
it gets somewhat muddy
ive been noodling on what we should call users of the fediverse as a whole