This is old news. McDonald's used to cook their fries in beef tallow, like everyone else. When the cholesterol scare came up, they switched to a vegetable oil blend. But the fries lacked the old beefy flavor, people complained and a flavor company developed a flavoring agent to match the original taste. Then came the blow up with vegetarians, who never ate the original fries because of the tallow. McDonald's has since switched to a flavoring containing no animal components.
I don't know about wheat. If it's really there, it's likely flour. McDonald's ingredients and nutritional statement for every item on the menu is available at every store. People on special diets can easily check.
The net is full of trolls who like to drive controversy with half truths and insinuations. Gotta to love the elegant phrasing, "laced with the blood of dead cows"!
Willie