Just looking on AOW for my upcoming flight YYC - LHR April 1st. It is showing:

J9 C4 Y6 M3 B0 H0
V0 Q0 L0 T0

Clearly a very full flight - though interestingly I get a total price of $740USD for YYC-LHR and back to YVR on 8th April. I would have thought it would be much higher given that one leg is M class?

My real question though was I am surprised it shows Y6 and M3. I thought it would always show Y9 when there are any other seats left in the other fare classes, i.e. Y9 M3 as they would obviously be happy to sell the M seats as Y fares.
Also C has gone from 6 to 4 in the last week. What happened to those two seats? We are not in the seven day window so no SE can have upgraded in the last week. What else is pulled from C?

No real concern to me, the fuller the plane gets the more chance of an operational upgrade I live in hope.