Originally Posted by mbreuer
One word of warning: Call to redeposit as soon as you know it won't can't clear. Otherwise, you a) won't be included in EUA and b) can't do OLCI.
Right you are, mbreuer! Although there is no charge to return your miles if you do not get the WaitList upgrade, you must telephone OnePass to get the miles redeposited into your account. And if you don't get the WL upgrade, you will be locked out from the EUA which starts roughly 72 hours before the flight (when the Platinum EUAs commence). It is wise to call to cancel the WL request and have your miles redeposited (all in one call) about 5 days out. Then hope for the EUA or Battlefield Upgrade. (Can we use "BFU" as an abbrev. for the latter?)
Incidentally, you can call for the free mileage redeposit after the flight, as well, if you didn't already do so.
My information is based on stuff culled from many OP Elite Line conversations with CSRs and from many prior FlyerTalk posts and from personal experience --- which makes this post 92.7% statistically correct (LOL).