You do have tenancy rights and you should check with the rent board. However, you should note that an illegal rental may be removed from the rental market by what's called a demolition eviction, and this is just cause for eviction under current rules.
If you want to stay I would make nice with the new owner(s), and you should probably consult with a Real Estate attorney to understand your rights. The new owner may prefer to buy you out and that may be more worth your while than staying.
And yes, Joe, great answer.
Lance King/Owner-Managing Broker