If the property management company represents the buyer, they should be prepared to prove that fact.

When the property is foreclosed, you would not want to pay any rent to the (former) landlord, unless they redeem the property and continue the tenancy. If you wish to negotiate with the purchaser, you can try to rent from them. In the alternative you can wait to see if they evict you. Typically when the new owner wants possession the new owner would give you a thirty-day notice to quit because, although a shorter "pay or quit" notice is possible, acceptance of rent would create a periodic tenancy.