The way I see it is that Ozil is more than comfortable here. He's settled in London, loves the city, loves playing for the Arsenal, the fans love him (well majority) and appreciate the class he brings to the team.
I doubt he ever wanted to leave. Some might call it lack of ambition or whatever, but players are humans too and sometimes personal happiness exceeds demands for trophies. No club has a right to win their league from the off (except for Celtic and Bayern) and ours is the toughest to win.
Sanchez may feel differently and less settled. Good luck to him if he feels City is right for him. If he goes, hope he gets nowhere near the title.