Inasmuch as a buyout is tantamount to a large stock sale, I would expect the provision you cited to remain in force in such a case. Are you sure it doesn’t?
I have confirmed this and the other relevant details with BPAX- their CFO handles IR inquires and is exceptionally responsive compared to peer companies. There are no payments due to AIS if BPAX is purchased in total. To no great surprise, I did not get an answer to the same question from AIS...