Just heard from a friend in a similar situation. They were advised not to cancel but to leave the booking live.
If prompted by the online booking system to select a later date they were told to ignore it. They were going to a now cancelled conference so there was no "alternative travel date".
Eventually the flight was fully cancelled but their booking was still active & not transferred to another day.
Phoned the airline, explained, got the refund.
Actual story as told but may not fit your circumstances -> DYOR.
