@Samantha-and-Matt0 That seems like an odd expectation. If that's what you were expecting, that should have been part of your sale agreement with the new owners, not something you spring on them after the fact.
You could have had the bookings cancelled under extenuating circumstances before you sold the place, and I certainly hope the booked guests were made aware that the property was changing hands and given the option to cancel with full refund- not letting them know and giving them a choice would be very bad hosting style.