Raiders fans thought he was going to be the next Wes Welker, but Oakland cut him earlier this week to sign a guy who was a teammate of Derek Carr at Fresno State.
IMO Willis' best chance to stick with the Bills is on special teams, giving them depth at WR if he's pressed into duty. He may get playing time in the next 2 preseason games if Rex wants to keep potential starters out of a situation where they could get injured.