Microsoft is basically moving it Ontario tech center from the Mississauga suburb to the core of downtown Toronto. If you want to attract top tech talent in Toronto you need to be located in the core downtown area. The majority of younger tech workers live in condos downtown. The majority of older tech workers commute from suburbs to downtown using public transit. Commuting from one suburb to another around Toronto is a pain. Google and all the other top tech centers are located downtown in Toronto. Microsoft is just following the others.
Funny, the millennial tech workers still can't reengineer legacy bank systems. They're still running cobol systems from the 80s with a new UI.