I wouldn't rule out Pulp. Although Jarvis didn't include it on his tweet, that doesn't mean it's not happening. The reality is that George Ezra probably shouldn't have included IoW in his announcement until IoW Festival had officially announced it themselves.
There's a massive gap in Pulp's schedule in June so I wouldn't be surprised if they're there. That said, there's also a big gap in Coldplay's schedule but I don't see them doing IoW.
I'm also hopeful we'll see Pink headlining but that may be wishful thinking.
Killers would be awesome although again, may be wishful thinking.
Lionel a distinct possibility.