I think that instead the article is probably referring to Luke's second lightsaber, the one he built himself. Which would mean somebody severed his hand again.
If this rumor is anywhere near true, it means we'll likely see Luke outfitted with a far more rough-and-ready prosthesis later in the film--if the apparent Mad Max aesthetic of the new trilogy is anything to go by.
Of course, the OT Storyboards book revealed that the idea of Luke losing his mechanical right hand was already thought up back during ROTJ.