I'm not even sure what we're arguing about here. Özil was Real's second best player at the time he moved. If people don't think he could have found a better club than Arsenal they're fooling themselves. He was lured in by a personal relationship to Wenger and the promise that we were building something exciting. Three years onward it would be hard for anyone to view that promise as anything but one big, fat lie. The fans know it, the media know it. Naturally Özil and his representatives know it too.
He seems like the type who's too concerned about his image to kick up a fuss about it in the papers, but first chance he gets he'll be out of here. There isn't a single good reason to extend that contract from his point of view, which is probably why all the rumours of an extension quickly died down as our season followed the predicted trajectory and disintegrated in February.
As for Sanchez, he's a top class forward in an era where there's a dearth of top class forwards. He could have his pick between Europe's top clubs.