Yes, that is the policy. What is written in the wiki on top is the same as they are communicating to their travel agents.
So if check-in agent follows policy, they will refuse to check to final. Not sure why he is about to redeem from 2 different programs on 2 different PNR onto one carrier (AY) but perhaps he has points spread over different programs.
I don't have recent experience neither, as I avoid either having bags or AY altogether when on separate tickets. But can confirm the wording in policy is still the same.