No, not from my experience.

My son is allergic to dairy and egg. He's 15 now but of course has flown since he was about 4 months old. First class to Hawaii is the biggest challenge - usually both choices on DL have dairy or aren't safe. I tried ordering one of us a veggie meal, but it wasn't great. We try to work around what he can eat off the plate, like the rolls (they give him extra), fruit, and sometimes there is plain meat.

I try to allow enough time between flights or before any flight to let him have a good (well, filling) meal. Then bring more food along.

The flight attendants do not know ingredients, so I've said this time and again - if you have an allergy, bring your own food! Yes, it may just be plain cold food, but it will be better than a reaction at 30,000 feet! It sucks but if you are truly allergic, you need to be safe. The FA's can't be responsible for that. It's too risky.