I hope that you are right as getting rid of his, (reputedly), disruptive influence would be a big plus. My only niggle is that it's his Agent who is claiming this huge interest. Call me picky if you wish, but I don't always believe football Agents. I know it's hard to credit, but I'm told that some of them tell porkies.
Someone will want him. He's a quality player. He's been disruptive but not to the level it will hinder him moving surely. Want away players get their wish usually from what I've noticed. Had he not had the relegation clause I'd be worried but he has it so he'll be gone I reckon. Don't think it will be soon though. I think it will be waited out till much later in the window as he'll be a big budget signing on the continent and that usually means a 'housing chain' style hold ups as they gather resources and move other players on.
He's one of the players who highlight the fine margins in surviving relegation and going down. You've got a handful of players who were well regarded (Kone, Januzaj, Khazri, Lens, Borini) who overall contributed almost zero to keeping you in the division. I'm sure they're great on Football Manager and some fans just look at a list of names and say "that's a good team". Ultimately the Bournemouth players are a much better team and it's something Newcastle and Sunderland need to keep working on. The whole Lens loan last season was odd from the get go. It's hard to fathom how a relegation isn't going to make him more willing to go than he was already (as he said pretty much) and I suspect he was out the door anyway.