I have an upcoming work trip where the onward journey is on UK and the return journey is on AI. After completing the online check-in and linking this trip with my CV ID, the list of upcoming trips in my CV profile shows both the onward and return flights across both airlines. Then I looked at the ticket more closely and saw that indeed the PNR for both journeys is also the same as well. Has this always been the case or does it signal some new development on the approaching merger completion due in the next few months?