Booked a first class redemption using Aeroplan for Etihad First Class (YYZ-IAD-AUH). All good until this morning as AC decides to cancel our flight from YYZ to IAD due to "fog". Lots of flights to/from yyz to iad that would have us being able to catch the Etihad flight from IAD to AUH.
System sends an alert saying the flights are rebooked and now its YYZ-DOH-AUH (economy to DOH and First for the last hour to AUH).

Call Aeroplan and they try to get us to IAD and find a number of options but our seats on IAD-AUH are cancelled and they can't seem to book them despite seeing availability. Seats blocked by Etihad. Apparently the aeroplan manager tries to purchase the seats with zero success and we are left with no options other than to cancel (which we can't as this is part of a larger trip) or rebook a different itinerary.

End up rebooking YYZ to AUH direct in business and they offer some point refund (TBD).

I'm confused about why aeroplan can see availability but cannot book anything due to the other airline blocking the seats. So frustrating as we were excited to experience first class cabin and were overjoyed at the redemption we had.

Anyone else experience this as the agent seemed so confused as to blocking of seats.

Thanks for listening.