Lifemiles had more award space than UA for a UA flight! (and is this any risk?)
This is kind of strange .... so wanted to ask the experts here if I have any risks or concerns ... I was looking to book a domestic F flight on UA metal. UA showed only mixed cabin awards on their own site for the entire travel day I wanted to fly, so I decided that's fine to sit in coach for one segment and went to book with a stash of Lifemiles that I didn't get to use thanks to COVID. Anyways, when I went to look up the flight on the Lifemiles site, LM had F availability for both flights, and actually, they had two options! UA had only mixed cabin awards for the entire day. After quadruple checking I input the right date on LM, I hesitantly tried to book it, assuming I would get some error message, but it went through and was ticketed (I confirmed the 202-X ticket number shows on UA site and was able to select seats in F for both segments).
How is it possible that Lifemiles had more award space than UA for UA metal? I'm certainly not complaining, but it just seems so strange. Aeroplan had only mixed cabins and Turkish had only economy (because their #@($* search engine won't ticket mixed cabin awards).
The flight isn't until May, do I need to constantly babysit this reservation, or should it be alright?