My guess is that their longish-term strategy is to have everybody logged in to their platform when they are doing business work. Using Word? Must log in. Out

My guess is that their longish-term strategy is to have everybody logged in to their platform when they are doing business work. Using Word? Must log in. Outlook? Ditto. They look like they are using SAAS to get the business software world back under their control. You can't do it all at once, of course; you'll have some edge cases to deal with. But if you can manage it you'll have tremendous leverage.