Hi there,
my 2 cents: PF is PF even during landing (unless CDR takes over for whatever reason), so he/she is responsible for the proper braking, whatever the PM call is.
"Decel / No Decel" is indeed a very good PM call for the braking effectiveness of the bird on the rwy, despite the green light which is the consequence of the proper braking rate.
But, as the golden rule states: if things (autobrake) are not going as expected, (PF) take over.. So jump on the brakes and stop the bird or quickly do the "loss of braking" memory items in case of failure..
Back on topic, I quote the braking feeling and speed trend as a trigger of the "Decel" call for effective braking.