It's probably being taped on the 18th so being that Richie is not scheduled to be back this whole leg, I would hope that he would NOT show up just to do Ellen. (like that is more important than being there for concerts) So unless he's going to be on stage for the LA show, Las Vegas show etc. etc. I would say that he's NOT going to be there and Phil will be on Ellen. Or they will be there with no lead guitarist at all, hoping no one will notice.