If a ticket is reissued or revalidated or is pending either, inside the 24 hour window of departure, then all appended services are automatically cancelled. Seen this happen with EY and EK, the CD gets cancelled along with meal requests.
Just had it happen to my uncle couple days ago, flying EY from MEL. The issuing agent did not revalidate the ticket as a result of a schedule change so couldn't check him online. I called EY who said to call back the agent. I raised the point about CD/meal requests, and the EY agent confirmed indeed they will be cancelled. So what we ended up doing is holding off from calling until my uncle reached the airport. The CD service was fulfilled. Called the agent, had them revalidate over the phone. Then since he was inside the 3 hour window of departure, his special meal wasn't affected as it was already loaded onto the carts. He had to confirm this with the service desk.