Based on the description of the map, the statement that is most likely true is:
Most Greek city-states and colonies were not former Minoan trading ports.
The information provided indicates various trade routes originating from Crete and connecting to other city-states and regions, suggesting that while Crete was a significant trading hub, the majority of Greek city-states located elsewhere, particularly along the western and northern coasts, were not directly associated with Minoan trade. The presence of many Greek city-states outside of Crete implies that not all of them were former Minoan ports.
The other statements regarding Minoan ports being predominantly in the north, in the west, or that most Greek city-states were former Minoan trading ports are less supported by the map details provided.