I have been reading on here that a lot of FTers were downgraded from F to E. How can UA do this?

I thought a "confirmed" upgrade is CONFIRMED and you are guranteed a seat in F?

Are you saying that if I bought a E fare and used my 15,000 miles to upgrade for a confirmed seat in F but it's not really confirmed and that I can be kicked back to E at anytime IF a pilot decided to sit in my seat?

How about those A fares that you book when you were initally booking in E but offered an upgrade to F at ticketing when you actually pay $$ to upgrade??

Im confused.

I mean, I understand if an Elite is WAITLISTED and then he/she gets a BP then is told that a pilot needs to sit in F and that unfortunately he/she has to go back to coach.

However, if a passenger pays the upgrade with miles, SWU, CR1 and is told that he/she is CONFIRMED, then UA can't just downgrade them!!!??

This is like paying for filet mignon at Ritz and then getting a sirloin at Sizzler, you bet I will make a scene regardless of the method of payment--cash ($$ rev) or gift certicates (miles, CR1, SWU).