I doubt it was suddenly, though of course I am just spinning conjecture: What I imagined happened is that Google told Microsoft that it's kind of ridiculous that they have to pay an ActiveSync license for Microsoft devices (which could have used other APIs...but wouldn't you know it Microsoft chose the one that made them even more money), some negotiating happened, Microsoft said stuff it, so Google pulled ActiveSync. It is truly a ridiculous situation that Google has to pay Microsoft to provide services to Microsoft users.

I'm no Google apologist (Page's statements about lets all work together etc were utterly ridiculous. I understand that he probably actually believes what he was saying, not realizing the destruction they lay in their wake), but Microsoft almost always has a nasty stink coming off of their complaints.