The only songs Amanda has ever written are blues songs and punk rock songs. Most punk rock songs involve no more than three chords. So if the next song Amanda writes is not a blues song, it probably will not involve more than three chords.
The reasoning in the argument that the next pet the Gupta family owns will probably be very noisy if it is not a fish is most similar to the reasoning in the argument that if the next pet the Gupta family owns is a parrot, it will probably be very noisy.