Thanks for the replies. None of this is good news if you want to make the most of the points earning rates for partner flights booked through AS and you want to snap up the better TATL Business Class deals which almost always originate in Europe somewhere.

Between this and the continuing lack of transparency surrounding the earning rates for 2026, I think I'll continue staying away from Mileage Plan/Atmos next year. With a bit of luck, AS will join the AA/BA/AY/IB cartel - that would sort things out