In good faith, I believe this was the original intent. Like a master key or the gold master record or cd. It is the highest original source of truth from which copies can be made and it was never intended for there to be something called or intimated to be "slave branches".
Unfortunately, there are enough concepts in our discipline that take this single source of truth concept and use the master/slave terminology. For an example Google "Replication master" and see if there are any articles on the page one results that don't reference "slaves". They all do for me when I do a query.
I see absolutely no harm in moving the git nomenclature of "master" to "trunk" or "base" some other term. Keep it as an alias and flag it as depreciated.
