If gluten allergies were actually glyphosate allergies, it would be trivial to demonstrate.
Gluten allergies exist. Gluten is a protein, and people develop allergies to all sorts of proteins.
> organic wheat does not come in contact with glyphosate
Organic crops do have pesticides in them, just in lower quantities. You cannot reverse half a century of pesticide abuse simply by rotating to organic farming in a few isolated places. It's everywhere, including the soil. Even if the farmer doesn't spray glyphosate, it still exists in the environment.
Wheat is also notorious for the amount of pesticide that can be found in it. Glyphosate is just 1 part of the equation, but that is another discussion.
Glyphosate famously breaks down after two weeks, but those are for the perfect conditions, and the advice is to increase water to disperse the chemical. Textbook half-life is between 3 days and 19 weeks, though under what conditions, they are a bit hazy. Still, I would be inclined to believe that number when it comes to wheat.
Glyphosate on other crops, particularly trees for example, can take much, much longer to disappear, if at all. Trees that were sprayed 12 years prior can still have glyphosate in their tissues (Canadian study). Root plants are particularly good at retaining and accumulating it.
Wheat is a little more special, because it is the most important crop of humankind, full stop. It is also protected by a shell, which gives the false sense of safety. Nuts too contain impressive amounts of pesticides because of the ubiquitous application, and the same perceived sense of safety. However, both nuts, wheat, and other grains hold on to pesticide very well.
If you were asking about gluten allergy specifically, I don't think that's about pesticides at all. At least I just don't see a convincing evidence. Though that doesn't mean pesticides can't interfere with the mechanism. Like practically all things with our food, we simply don't know the answer.
> even meat?
Pesticides are present in meat, though they are in lesser quantities iirc. We have laws against antibiotic use in farming for a reason, they too contaminate meat very easily. Though, at least with antibiotics, if you cook the meat for 45 minutes, their bactericide effect is almost completely broken down. I say almost, because that, we also don't know. The best research that I know was conducted by Iran, so take that with a grain of salt.