I haven't catch-up all the reading on this thread yet, but are we sure it will not work for Market Fares? I understood the chart show Aeroplan Classic, but as you stated, Market Fares is not "X" class, so it might work.
Anyone here got a Market Fares ticket before Jan 9 that can try to put it in the eUpg account and see if it will show "Upgrades can only be requested within 1 days of departure." or not?
I've got one in October that when I put it in says "Upgrades can only be requested within 14 days of departure." So, that would seem to indicate it is upgradeable.