Any Artist on the up for starters. Harry styles being a massive one. Green day rumours even though not on the up having never played the festival and still doing stadium tours would of been a good slot, exact same with the arctic monkeys rumour.
1975 about to release new music, were touted to headline before COVID, could of been a good refamiliarization before they get the top slot.
Jack white on the other hand wont be headlining any time soon. wont be popular with younger demographics. seems abit stagnant for me.