Originally Posted by
corporate-wage-slave
The rebooking allowance within ticket validity comes from the cancellation, and ticket validity is to the October date, so I would assume a booking agent would allow that. Since you don't currently hold a valid booking then you are in scope for the Coronavirus guidelines. By all means ask the agent simply to reissue the tickets for December as the first line of approach, but it's outside the policy.
I called, BA agent said "I see there's been some cancellations," I said that MMB had booked new flights but timed out reissuing the tickets. The agent said "Let me see why it had a problem...." then said she saw availability on the dates/flights that MMB had booked, so she reissued the ticket!
Interestingly, I'd called multiple times when only the original one return leg flight was cancelled, and each time the agent said only the return flights could be adjusted, and only plus/minus 14 days.
I'm pleased that my flights were moved from February to December. The only downside is that as that's past the end of the policy, any further changes requires a change fee as well as fare difference (previously, MMB allowed completely free changes as long as the original booking inventory was available). As December is a long way away, I hope BA extends the policy. I'm not intending any further changes, but you never know.