Off-topic, but I'm sure Disney didn't
suddenly decide to do anything.
Back on topic, it's not plausible.
Visitors are asked about the Dining Plan so the server can advise them: how to use it, inclusions, and (rare) limitations. There is no secret code entered into the PoS informing the chefs to skimp on some orders. The
DDP is not the real it once was. Frequently, diners pay
more using a dining plan than they would out of pocket.