This honestly wouldn't surprise me because everything else with this line up is a bit too good to be true at the minute for those of us who long for the days of seeing a festival replicate the old Leeds and Reading type line ups of the mid-00s haha!
Linkin Park, A7X, Slipknot, GNR, Fontaines DC, Idles, MIW, In Flames, Biffy, Circa Waves, Lorna Shore, Spiritbox and Jerry Cantrell (plus more) is proper value for money in the modern gig world for £220(ish) a ticket in the modern world. You'd imagine something has to give somewhere and bumping a Czech rapper to headline would probably work for them, as much of a shame that would feel to someone debating coming from abroad.
He doesn't have the pop hits, but tracks like Cinnamon Girl, Heart of Gold, Hey Hey My My, Needle & The Damage Done etc are still classic rock staples.
Saw those two acts on the very same bill in Perth last year while I was abroad. Was actually a very fun show, and given they've just run arenas together in November, can see this being a quick sell.