Nobody will use N3 (original), it's a shit experiment that only Apple signed up for, and will be dead node as soon as Apple stops using it. All other N3 customers will start on N3E or N3P, which are just starting production. So there's no "freed up capacity".
Nobody will be using N3 for this product either b/c they will pay $$$$ out the ass for all these CCDs. Neither do they need N3's characteristics - server clocks low, dense core probably even lower. At least until N3E/N3P becomes a mature, affordable node (like N6 was last year, like N5 was this year, like N4 is becoming now).