It just seems highly unlikely this guy would get the scoop, he's not broken anything about United, ever. He's just playing the odds and making his article controversial (and therefore popular) by releasing it now.
Ineos have undoubtedly spoken to a load of managers, I'd be surprised if it's not 10+ but that's just what good schmoozing is about even if you're not looking to change, there's no way they decided in the recent past he would be fired though, it was either a decision made yonks ago or it's yet to be made.