If it is a meal where items must be ordered from a menu where prices are listed, and is brought by a server, then there is never a per-person charge. A mandatory per-person charge is ONLY for a buffet (such as Hollywood & Vine) or a meal that is served family-style (such as 'Ohana).
I’ve heard of non-Disney restaurants mandating a “sharing charge,” but I’ve never ever heard of a Disney restaurant charging someone for a full meal just sitting there, IF it is not a buffet or a family-style meal. There could be some sort of sharing charge, but it would be nominal.
The whole “you’ll be charged whether you eat or not” … how could that even happen at a non-buffet, non-family-style table-service restaurant??? If this was at a “traditional” menu meal such as at Brown Derby, what on Earth would they say: “OK, well it seems your 4th person who DIDN’T EAT would have ordered the seared day boat sea scallops appetizer, followed by the pan-roasted duck breast with venison sausage entree, strawberry cheesecake and a Diet Coke, so we are adding $50 to your bill”??? I don’t think so. WHat did they charge your party for, monrailrider???
Calling Disney with such a question will do no good. The cast membes who answer the 407-W-DISNEY calls are NOT experts in all things WDW … they are trained only in resort reservations (not whether they have towels at the pools … strictly reservations), dining/special event reservations (not if a dish has peanuts in it or if there is a sharing charge … strictly reservations), and ticket SALES (not the USE of tickets … strictly SALES). Unfortunately, many of them will provide answers, anyway, whether or not the answer is right. Sad, but true.