I think a lot of people forget the trade off between clubs and players regarding contract length.For clarity, Kane for me can leave, he has done his time and given us mostly everything, apart from turning up in some really big games when it mattered but he can only leave on Levy’s terms as that’s the deal he made with the Devil when he signed a 6 year deal.
Players (and specifically their self-interested, thieving agents) will always want shorter contracts - more freedom, more signing on fees, etc. Clubs will always want their best players on longer term contracts to protect us against anyone doing a Sol clambell. Kane will, at some point in the negotiations, have received a higher salary in return for having signed such a long contract.
Doing so was his choice. He doesn't get to move until the end of that contract or until we choose for it to happen on our terms.
He should remember the short, tubby fudger he was before he joined us.