Was certainly possible for Plats until recent years, way after 2012, as I used it a few times, maybe as an 'exception' who knows - just around COVID hitting as I recall was when it was tightened, along with lounge visits on Arrival for same stated reason. Then it was canned
'due to social distancing ratios' if I remember, and that part never came back it seems.
Buying a Flex fare and cancelling seems to incur a $99 fee sadly, so not prudent.
And Biz cabins late afternoon are full, with paid pax and upgrade bidders generally. But seems like they can be cancelled close to flight for a full cash refund?
Oh well, was just checking the actual rules. Will head to a pub somewhere.