I'm pretty sure that's an urban myth in the UK; it is absolutely not the case here anyway. Commercial music stations (UK and here) have their royalties worked out on their turnover, number of songs or how they are played are irrelevant.
One of the two stations I work for have live overnights...
Gets more tracks in to the same amount of time if they talk over the intro rather than leaving gaps; useful if stations market themselves on "more music" policies.