Not sure if that means the start up of a new Saudia LCC. It could also mean reduced prices on some flights.
They are begining to see some competition in Kingdom so I'm sure they have to respond.
As for the new Airbi's, the A300's and old 747's need do need replacement. As they are meant for the Hajj, I would have though more likely a mix of second hand 330/340 's