The resolution of Polymarket markets for June 19-20 had nothing to do with what happened on June 21; those earlier dates had their own finite timeframe for action.
There are simply no resources to retroactively change a past market outcome based on future events, no matter how related they seem.
It's like expecting yesterday's lottery numbers to change because you bought a ticket today—the opportunity for those previous days is gone.
Each market had its own specific deadline and outcome, completely independent of later developments, conserving precious time and liquidity.