It’s true that wheat isn’t the same plant as it has been for most of human history. Holstein cows are relatively new and might have some different proteins in their milk. Much of our food is heavily processed or contains all kinds of synthetic chemicals such as pesticides, preservatives, flavor enhancers, etc. I’d be surprised if those things, especially the latter, didn’t have an impact on our health.
However, I have tried some of the exclusionary diets in question. I think that my general inflammation levels might have been a little better on a low-carb/non-wheat diet but I still had allergies. Ragweed and tree pollen seasons were still brutal. Taking honey and probiotics might have helped a little but that’s hard to quantify because “allergy seasons” vary by actual pollen levels and a lot goes into determining that. Going off dairy might have made me a little less phlegmy but as with the other benefits, notice the “might” and “a little”.
I’m all for better quality and more natural food. At the same time, I know that allergies are a learned malfunction with the immune system. I wouldn’t expect them to wear off any faster than your immune system “forgets” the immunity it gains from vaccination, and that’s usually an immunity to something you’re not being exposed to every year.