I'm a SE MM using an AC Flight Pass YYC-YVR-HKG then on a separate Thai ticket HKG-BKK. The YYC concierge said first it was impossible due to an IATA policy. Then said it was AC Policy. The HKG Concierge had said YYC could do it with the baggage agreement with Thai.
I'm getting assistance from the HKG Concierge on arrival and hopefully the bag will get retagged without too much trouble.
This policy is a particular problem for people using a flight pass as it's impossible to get a ticket to anywhere not served by AC that has that destination on the flight pass ticket. It makes connections more difficult and delayed baggage more likely and sometimes may mean you have to enter a country to retrieve bags and recheck them in if the transfer counter can't get them retagged. It also means the Concierge on the AC destination end has to deal with something that with Star Alliance should be easy. It greatly diminishes the value of an international AC flight pass. Policies like this should allow some flexibility when their impact on Flight Pass holders can make future flight pass purchases questionable

Pleasant and helpful HKG Concierge Ken arranged bag transfer for me with Thai.