It'll probably be similar to Fatboy Slim in 2023 i'd guess. Up against Neil Young and Charli XCX who respectively will have similar levels of appeal as Guns N Roses and Lana Del Rey had.
It's not going to rule her out, just artists of that scale aren't usually headlining the garden. I'd have said they'd put their best foot forward with their first announcement. And on the history of this festival, I'd have said a lot of those acts would've been high up. I also doubt with their health Godspeed would come back to Europe so quickly (and I don't think they're big on festivals anyway)