That means that the label like that producer/studio for their artist enough that their HR actively pull up contracts for said producer to work with their artists. Producers work for labels on a contract basis, whether its a single contract or a guarantee to work with a certain number of artists comes down to what the producer and the label wants. Usually though, for more famous bands/artists, they go to the producer that they want where newer bands are given to producers that have done the labels other bands within that genre that have time and wish to take up the challenge/want work.