My Aone agent will make confirmed reservation in club world if A is waitlisting as my dates are specific and not flexible. However in all cases by the time travel comes around A has cleared. Thats BA but I had similar with Cathay last month booked me in L on an AONe where there was no F on the flight and D was full by flight time D cleared. I saw a rule somewhere that you can go in A, D , L if available. I am sure someone will highlight the rule