I don't see it as the big issue others are saying. It is a long, long time away in football. It's longer than Pochettino or Koeman spent at the club.
By that point there will be a whole different crop of good, bad, upcoming and on their way out managers in world football.
And personally, if we end up pushing the Europa League places in the next two years (which I think we will after this summer) there is no chance he walks out at that point.