Not just hypothetical. I booked a F DC award flight on OZ from ICN to FRA in April. It appears on the LOT and Lufthansa sites as being in Y which of course panics me. However, the seats shown are in F, as too is the baggage allowance indicated. I went to Asiana's office in London to try to clarify this and they just shrugged their shoulders and said what's the problem the booking was definately in F.

Time will tell!