in your opinion.
but then, of course, your opinion is fact obvsiously.
Being so aggressively abrasive really doesn't help make your case.
There are more important things going on right now and throughout history there have been overreactions followed by corrections.
Likewise our language has changed many, many times and will continue to. There are many phrases from my formative years that 99% of people wouldn't dream of using now.
Just my opinion, but an evidence-based one. Instead of master/slave how about parent/child, trunk/branch, primary/secondary, I'm sure people better with synonyms than I can come up with something.
Github can use whatever terms they like. They are owned by a huge corporation. Their cash, their platform, their rules.