Last August, a relative bought a crazy Basic Economy Fare of $279 RT France to SFO on LH and UA with perfect connections. No kidding. $127 fare and $151 taxes. Ha!
She just flew to SFO. We are getting her a LH J seat on UA miles for a later return.
We don't mid throwing away half a $279 ticket, but I wonder if United would throw us a bone for canceling rather than no-showing. That way they'd have one more seat to sell. I'm thinking maybe a waived change fee on the J ticket if a better J option becomes available?
Hmm. I'm not sure you're asking the right question.
UA doesn't care if you cancel. If you don't check-in, your reservation will be cancelled regardless. You get no props for cancelling in advance. UA assumes some percentage of pax won't show up. That's how flights get oversold, when they estimate wrong.
The right question is whether you're going to get in trouble if UA figures out you're throw-away ticketing. Which you're making pretty easy for them using UA miles in lieu of the discarded return.