More than a couple of people have suggested making it possible to remove/cancel/undo/whatever a moderator flag. Some seemed to be worried about flag weight or whatever. (I know "flag weight," per se, is gone; that doesn't mean mis-flagging isn't monitored.) I don't care about that, I care about wasting moderator time, and avoiding silly misunderstandings.
There is exactly zero reason why a moderator should have to look at a flag I've raised if I see that the reason for the flag has been corrected, and it leads to seemingly-nonsensical flags (because by the time the mod sees them, the situation isn't as described) and nonsensical replies to those flags from moderators (because things have changed).
This can be avoided by giving users with sufficient rep (or whatever other measure you want to use) the ability to remove their own flag prior to a mod getting to it.
Most of the requests for this (e.g., here, or here) don't actually have a
status-declined on them, but overall it seems as though there's been a decision not to allow users to cancel their own flags. Could we revisit that?