The title couldn’t refer to Anakin because he dies at the end.
Sure it could.
Anakin’s Return is a big deal in the film. He doesn’t just show up n’ keel over, he returns & saves the galaxy by killing the Emperor. He also Returns proving Luke right & Obi-Wan wrong.
“I can bring him back to the good side.”
Anakin’s Return is the crux of the film!
Again, not saying I’m right, but there’s nothing that makes this idea “wrong”.