True enough, but that should be accomplished through transparency only.
EG, "Our product contains $Ingredient"
That leaves it up to the consumer to evaluate "$Ingredient is on my DENIED list.", and rightly choose not to order, when and where appropriate.
The issue, is when the customer goes to a place that has asserted "Our product contains $Ingredient", and demands "I WANT IT WITHOUT $INGREDIENT!", then makes some moral soapbox grandstand about it.
I get it-- people with celliac disease cannot eat gluten. If they do, it tears them up inside, both figurative and literal. That said, perhaps that means they should avoid a bakery that specializes in whole wheat bread. This is because, while it certainly *IS* possible to make bread without gluten (It requires some tricks involving alternative proteins for the bread matrix, such as adding glutamate "glue", or egg white, or some other binder), keeping the work area free of wheat flour (which contains gluten, and is what most of their products will be made with, so it needs a special work area with special ventilation, and special procedures to assure freedom of contamination) is an onerous imposition on the baker-- Especially since they SPECIALIZE IN WHEAT BREADS. Demanding gluten free from such an establishment is just straight up pretentious.
The unmet demand there (demand for gluten free, but wheat bread specializing bakery cannot easily satisfy), if sufficient in the local economy, will result in specialist bakers that do not use wheat flour (and thus can assure gluten free status easily).
Otherwise, the appropriate action is to bake your own bread, rather than raise holy hell about how the local baker does not cater to your dietary requirements. You can assure that your bread does not contain any wheat or other gluten containing cereal grain flour that way.
There is nothing wrong with holding ethical exception to eating animals or animal products; but demanding concessions out of people that do not share that source of moral indignation, to the point of causing systemic disruption and public spectacle, is going too far, and is unacceptable. It's just as annoying as having the Jahova's Witnesses beat on your door every morning, once they learn you are an atheist-- but with added economic consequences. (The special conditions that need to be met to observe the demands properly greatly reduces profitability of the business, and the vocal complaints on social media can drive down sales for "non-compliance"-- All because people refuse to be reasonable and be considerate of the circumstances of service providers along with their own needs, and instead want to prioritize their own needs 100%, 100% of the time.)
Take for instance, the frytop grill at a burger place. Under normal operating conditions, you need to clean the frytop only after X number of patties have been fried. However, once Vegan Social Warrior enters the building, you would *HAVE* to stop all other patties frying, thoroughly clean the frytop, THEN prepare the SINGLE vegan patty, before you can return to normal operations. That introduces very significant lost opportunity penalties to the operator, especially if the order is made during a peak business hour. "It took forever for my veggie burger! I will bitch on social media!" is a manifestation of this failure to comprehend the impact of the demand, from an establishment that does not specialize in vegetarian cuisine. The same would also be true from an omnivorous patron, blundering into a vegan specialty shop, and demanding a fat greasy hamburger made with 100% pure beef.
I am pretty sure the vegan would consider such an oafish omnivorous patron to be simply unbearably intolerable, and would decry the action stridently-- but the inverse never seems to be considered at all.
My angle here is not to say that vegans should never order vegan products from a national food chain--- Just that being conscientious themselves, will go a long way toward being treated conscientiously. That means "No, dont get on your soapbox and throw a hissy fit; Understand that your order is an imposition, and respond accordingly." It would be the equivalent of the omnivore showing up at the vegan fast food place, and stating "Hey, I know you don't normally serve this kind of food here-- please prepare all the other orders you have first, and then if you can, please make me a double cheese burger with bacon. I am patient, will wait contentedly, and will pay extra." He is much more likely to get that double cheese burger at "Beans and Things", than the offish, "AHH WAN' MUH CHEEEESE BURGHA!" obstinate ass. The same is true of the ethical vegetarian, going to Burger King.
Sadly, all too often, vegans tend to be in the "Holier than thou art" category. (like the omnivorous tend to be in the offish "AHH WAN' MUH BURGAH!" category.) As such, they seem to cling to any and every opportunity to throw shade on the notion of eating animal products, pretend that it should be a moral privilege and imperative to prepare their food to their requirements, etc---
There's nothing wrong with being vegan; just don't be an ass about it. Same is true for being omnivorous-- just don't be an ass about it.