I guess if the flight attenedant calls up in the last hour of flight and says "someone has to go to the bathroom, what should I do?" My suggestion to the captain will be "let them pee in the seat, then write up the seat at the outstation." Hopefully, after several hundred replacement seats are flown to outstations and several hundred flights are delayed/canceled, some common sense will prevail. My guess is that most captains will employ the "if they gotta go, they gotta go" rule.
Oh, and I checked out Bulletins, still nothing. When did this come out? Our last domestic leg left at about 11am est.