I'm not sure if that's the case with most airlines. I always request vegetarian meals and used to get upgraded with some regularity on UA due to my 1P status, as well as on other US based airlines, and also recently on QN. They'd just get my veggie meal from the back and serve it on better china - no big deal. (A lot of times, special meals are the same in all classes anyway. Last week, I was served the identical meal on TG HKG-BKK in Y as my friend on CX HKG-BKK in J - this was ticketed in, not upgraded to, J. Same salad, main dish and dessert!)

In any case, I'd like to hear about people's experiences - and especially policies if you're an airline insider - with Asian and European carriers on this matter.