I don't think so. A "confirmed" passenger only has it confirmed that there is a reservation for a seat on board the aircraft. And the T&C of pretty much every airline make it clear that the existence of a reservation, even if "confirmed", does not mean that there will be any seat on that aircraft for that passenger, let alone any specific seat.

So whatever the commercial merits of pre-allocation of seats, I think this statement must be a complete non-sequitur.