BOM flights cancelled

i see there are now two LHR-BOM flights cancelled in late january, and the corresponding BOM-LHR returns
the first to go was 21st yesterday, which i found out about as we were booked on it (they moved us to 22nd, but i asked to be rebooked on 20th which was done)
but i noticed 26th has gone too
i'm assuming this is due to low loads in the last days before the route is closed down
it's a special holiday for us, our hotels are prepaid to get a good rate, but no refunds so there's no flexibility, and our return date is cast in stone due to commitments in uk
as we're on reward bookings (UC out, PE back and looking for Gs!) i assume we're at VS's mercy, but i'm wondering what happens if they pull another flight affecting our return, presumably we can't expect to be booked with another carrier
the first to go was 21st yesterday, which i found out about as we were booked on it (they moved us to 22nd, but i asked to be rebooked on 20th which was done)
but i noticed 26th has gone too
i'm assuming this is due to low loads in the last days before the route is closed down
it's a special holiday for us, our hotels are prepaid to get a good rate, but no refunds so there's no flexibility, and our return date is cast in stone due to commitments in uk
as we're on reward bookings (UC out, PE back and looking for Gs!) i assume we're at VS's mercy, but i'm wondering what happens if they pull another flight affecting our return, presumably we can't expect to be booked with another carrier