It is not in the TD Center, its at CIBC Square. Been there for 3 days early April, it’s a really nice office, with lots of space. Views are great too, you can see all over the city and lake.
Searching on Google Maps, it looks like the "HQ" is located inside Toronto-Dominion Centre, which is an office complex downtown, nothing too exciting to look at.
Pics of inside at https://www.blogto.com/tech/2022/05/microsoft-new-headquarte... it doesn’t show too many of the meeting rooms and work areas though :( it is open plan, well lit, well furnished. Mirrors other recent MSFT offices.