Even if gatekeeping weren’t a basic social hygiene practiced to some extent by virtually every group (it is) I don’t think it’s false to think a Forsaken fan who’s actually into what the race was about would find free will pretty important.
“We must respect our dead,” Vanilla tells you at level 3. “It is one of the ways in which we differ from the Scourge.”
Sylvanas, personally, has always played fast and loose with that principle.