There is the Maw Walker, singular, who is canonically the one basically everyone who’s who on Azeroth/Bolvar asked to come to their aid, and then there are maw walkers, plural, as any mortal who ventured into the Maw and came out on the other end alive and well post-Maw Walker can be called by. The title is meaningless to everyone outside of the Shadowlands, but it’s not exactly farfetched to claim to be A Maw Walker or even The Maw Walker.
People will probably not care one way or another on Azeroth.