Being a regulator is like being a teacher. There is one kids who keeps putting crayons in his nose so you make a no crayons in your nose rule to stop him and it works great until this one kid uses crayons in nostrils to make amazing pictures for a talent show and suddenly the first kid says "hey I thought you said no nose crayons, why is she allowed crayons now"
The main problem is that it's actually super hard to have a regulatory definition of "milk" that forces the dairy industry to not put stuff in milk, but also allows up to 100% of the product to be oats.
Vegan steak will be difficult for the same reasons. But I would guess vegan sausage, burgers, nuggets, boneless wings etc... will be very easy to approve since some products are already more fillers than meat already lol!