While all this may be true, it's not in Arsenal's interests to keep the player (on high wages no less) if he wants to leave. This scenario is even less likely than trying to hold onto him only for him to walk for free at the end of the season, leaving copious egg on Arsenal's faces and ruffling the feathers of the board and investors, the only group actually happy with Wenger continuing.
Once the player asks to go then the club are obligated to sell him. If he ultimately wants to go to City, it's between the two sides to hammer out a deal which would be acceptable to both.