FWIW, if you've upgraded that ticket with miles and the fare drops later, it's the TCV less the admin fee as well as the $50 WPs redeposit fee (for non-Plats) to redeposit the upgraded award and reissue it.

Really a pain in the arse if you ask me. Had a fare drop by $75, but would have required the admin fee plus the $50 fee.. wasn't quite worth all that hassle...