Disagree, it has been
'a thing'. Both music and film use the term
'master' for production and release. One would make new releases/mixes from masters. Much like one may
branch with a repository.
Now, I'll entertain conspiracy for just a moment. There might be concerning roots here with property or ownership... but if that's the case, the problem isn't with the language being descriptive of the system in which it operates.
We won't 'kill all masters' by getting rid of the word. My real conspiracy theory is this is one of many attempts to sow division. Nation-state nonsense.