His contract runs out in 2020 so you expect him to be around for another season or so before he goes to China.
He will be there longer than Pep that's for sure.
Maybe, but it could be the other way round - I couldn't really see him leaving before the expiry of his contract prior to this season but I get the impression that he's struggling a little to adapt to Guardiola's style of play. Maybe that will come in time but if it doesn't then he may well be on his way before Pep leaves.