Her crowd in 2023 at sub was tiny, yes it was raining but felt really small for one of the big acts, not sure she fits the vibe of the festival enough for headline
So as mentioned, Green Day, Sleep Token and Korn are the heavily rumoured bands for Download that reliable info points at.
There is the question though of what Slipknot are gonna do, as it would be really unusual for them to come over to Europe to play fests and not do anything in the UK.
There's also a headliner that Nova Rock and Rock AM/IM haven't announced which could be Linkin Park, given they are expected to do Euro fests next year.