It's about time. In fact, it's way past time. But don't expect Microsoft to give up without a great deal more fight, a legal challenge or two, and other tactics from their vast playbook.
Apart from that, simply resistance from users, who are not really "computer people" and basically know that clicking the "w" icon launches the application on which letters can be drafted, is not a small matter. I hope the training programmes are well planned to cover that aspect.