AS no longer plays a role in deselecting domestic passengers. It is merely a conduit for data between the passenger and DHS.

While there remains a very, very, very limited random deselection process, if one has properly entered one's KTN and the data associated with that KTN, one should expect 100% hit on Pre-Check. That is true for all carriers participating in Pre-Check, not just AS.

If you are deselected, either your KTN is entered wrong, your name does not match your KTN, there is a glitch, you truly just had some bad luck and have been randomly deselected, or TSA has revoked your Pre-Check.

International departures and domestic connections following an international arrival are slightly different.