bcflyer
As a side note it will now leave hundreds of cabins unattended every day when the pilot of a 50 seat aircraft uses the lav. (1-50 rule)
While I'm not sure that "hundreds" of cabins are left unattended every day (are that many pilots incontinent?), that procedure is not at all new either. Many of these aeroplanes have had the procedure since the doors were changed in 2002. See the Guidance on Developing Procedures and MEL sections of the AC:
AC 0215 Flight Deck Door Regulations - 7 February 2003
The FAA has also required such a procedure of their air carriers for many years:
3-47 PROCEDURES FOR OPENING, CLOSING, AND LOCKING FLIGHT DECK DOORS.
B. Certificate Holders’ Procedures. Certificate holders’ procedures must include at least the following:
1) Normal procedures for opening flightcrew compartment doors to include:
f) Procedures for two person flightcrews, when one flightcrew member leaves the flight deck
(i.e., a F/A must lock the door and remain on the flight deck until the flightcrew member returns to his or her station).