We typically distinguish UNIX® which is everybody who has money and wanted to say they're Unix, from just Unix, meaning the things that in practice behave like Unix.

Money talks, so I'm confident that Apple will get to call their mac OS UNIX® until they don't care regardless of whether in any useful sense it's still Unix. On the other hand, regardless of whether some organisation pays money to effect this, Linux is still Unix and so is FreeBSD.

You've probably seen other situations in the real world where the thing you actually care about is distinct from legal status - because our social cues aren't tied to legal status. That doesn't make the legal status worthless, but it is distinct - Obergefell for example is a case where doubtless normal people just accepted that these guys are married - there was a ceremony and everything, but in Ohio at the time the asserted legal status was that they aren't married, therefore the death certificate claims otherwise and hence the case in front of the Supreme Court.