I don't believe that in the slightest considering Jones will be back by then and that's the obvious place to have him. Pereira will likely fight again by then, and having them on the same card is an obvious move to make.
Edwards also needs to fight and UFC 304 is only rumoured for England, not confirmed. So there or here make sense as 305 is likely just DDP/Adesanya. But Ilia on 304 makes sense, especially if it is in England, as well as for 305 in Perth if it's a Volk rematch.
There's just no way Ilia is the headliner for 306. Best case scenario is if they placed him with Sean O'Malley where he'd headline then by default due to being the higher weight class, but even then it makes no sense to do those two over Jon or Pereira, who have to headline by default.