Not sure what Marvel is embarrassed by the name Power Man? Luke Cage is a hero and although his Wonder Woman tiara and bracelets were lame; I think making the progressive alterations to him was good but I think his title should stay.
It's been a long time since Luke used the Power Man title, though. He gave it up in the '90s. And there's currently a different Marvel Comics character using the Power Man name, Victor Alvarez. For that matter, Luke was the second Marvel character to go by Power Man, the first being a villain (Erik Josten) who would later go by Smuggler, Goliath, and Atlas.