We were booked BKK March on a 241 in BA J and got cancelled as well. Called BA and they popped us onto QR to Doha and then QR to BKK (Q-Suites both sectors) and then CX BKK to HKG and BA to LHR. All very painless with no fees (rightly so) and we got the seats we wanted. It’s worth a call to BA if you want to plan ahead/hedge your bets that Thailand will be open by then and don’t mind the Doha/HKG connection and at worst, you get your Avios and taxes back if it doesn’t happen and you end up glamping in a green and pleasant English field (shudder, come on Thailand!).