I heard that there is nothing that prevents the service centre from processing your case, even though your's is retrogressed. Having said that, you will get RFE etc on your case, however, the final approval will come only when the PD is current. In short, they are processing the case, but not going to give 485 approval untill PD is current. The good part is since they are processing your case, you can expect approval letter as soon as your PD becomes current.
