Actually it is... it's not too different from what it always was. In the past, it was about businesses running "Back Office" versions of servers in the office. Because NAS boxes are now a good enough option in small businesses, and many are moving their hosting into more prominent cloud services, they are positioning Azure to be the platform of choice for windows based services and applications. They've got Office365 to handle the mail server duties people lost moving away from back office. As a small business you no longer need to self-host anything (other than maybe a local NAS box).

I hate sounding like an advertisement for MS, but it really isn't THAT much of a pivot. More adapting to keep those parts of income that used to come from server licenses now as services. Not even mentioning Azure as a target, which is probably the best bet for keeping legacy apps running while transitioning/refactor/rewrite to new generations.