Which one, in regards to breeding?
Generally a lot of species of fish require warmer waters than their usual living conditions, in order to breed so it's probably possible to control breeding this way. Although in regards to platies I don't think you can stop them
If fry grow up faster in warmer water, so would the embrios I guess and therefore it will take longer in cold water for the fish to give birth in comparisson with warmer but I am just speculating from the back of my head, which is mostly empty