I don't understand the logic either. Matt Bellamy is a guitar virtuoso and a one of a kind vocalist... Dom is an insane drummer, and Chris is an amazing Bassist! This is the perfect formula for Rock Band, yet there has been NO MUSE IN SIGHT. If the band's tunes were available, Rock Band would have capitalized due to how requested they are. Guitar Hero has had a Muse track in every major release since GH3 aswell as ExoPolitics, Stockholme Syndrome, Supermassive Black Hole (DLC), and Matt ingame in GH5.
Keyboards will not change their status in Rock Band, and a game dedicated to them WILL NOT HAPPEN unfortunately (they aren't Tthe Beatles, Green Day, Metallica, or Aerosmith). It wouldn`t be a smart business move.