Originally Posted by
nov11
I am under the impression that the Y/B/M upgrades clear into a different bucket (FE/ZE?). Thus, there is no need for IM to pull and reinstate R/RN availability before the sweep.
Well, if they wanted to hold FC space for the YBM-UPs, but they also wanted to allow instrument upgrades, this would be a reason for withdrawing/reinstating the R/RN inventory.
Perhaps they're moving toward different inventory buckets for instrument upgrades and EUA/UDU/CPUs (e.g., R vs. RN) in which case they wouldn't need to do this.
FWIW, AA has different buckets for mileage and elite upgrades. Although their mileage upgrade bucket is also a revenue bucket on domestic 2-class flights for some stupid reason... (Which of course is good for travelers as it means mileage upgrades are almost always available on AA.)