I can see Wombats there. I don't think fontaines are bigger enough to headline.
Royal Blood I feel would be most likely as they have unfinished business with the festival.
Other potential headliners I was thinking were- Jamie T, Bloc Party, Glass Animals, Jungle, Biffy Clyro, the Black Keys
Could also see some these bands appearing- Frank carter and the rattlesnakes, fontaines, cleopatrick, Pale Waves, loyle Carner, yonaka, The amazons, wet leg, self esteem, beabadoobee, Arlo parks