In the aftermath of Germanwings 9525 in 2015 many airlines instituted a two-person rule for the cockpit (aka "two-man rule") - with a flight-attendant replacing whichever pilot left the flight-deck.
In 2017 the industry rescinded that rule. Articles about the repeal of the rules don't mention what alternative processes are being used to prevent another occurrence of sole pilot murder-suicide - or a hypothetical where both pilots have suicidal intent - or when a single pilot is incapacitated while the other pilot is out of the cockpit for medical reasons or other reasons?
The problem being that while the reinforced cockpit door can be opened with an access-code, the occupant of the cockpit can countermand (indefinitely?) the access attempt. Has that policy been changed?
What safety-rule or practices are being instituted to protect against this - or is the pilot murder-suicide scenario being removed from the threat-model entirely? (so if I see one of the pilots banging on the cockpit door while in flight I should resign myself to my fate?)