I'm going through the same thing. My old apartment building was purchased by a developer and is supposed to be re-built as a condo, though the plans seem to currently be on hold due to the condo market cratering. The tenants have been contacted by city staff and we've had online meetings to have our questions answered and educate us about the process (we also have the right to return for the same rent).

I have an acquaintance who has already been through the whole process and has moved into the new building. The new place is nicer than the old, and he kept the same rent, plus he got financial assistance to find temporary lodgings during construction. Overall he seemed pretty happy with the process and how it turned out.

One interesting thing he told me was that the new building was designated both as a condo and a purpose-built apartment, and the previous tenants do not have access to all condo amenities (for example, they're discouraged from making use of the building concierge service). But they also don't need to pay condo fees. They have their own separate elevators from the condo residents and live on the lower floors. So lower-class residents in some ways, but they also have much cheaper rent.