This is really not a new idea.
For many years, I could get what our local Krogers and Big Johns called "patty mix", which was part beef and part soy. It was always 10-20 cents cheaper than hamburger, but had less shrinkage, as they replaced a lot of the fat with the soy product.
I could tell a bit of difference in burgers and meatloaf, but my family didn't notice it, and I couldn't tell any difference at all in things like chili, spaghetti, casseroles and such.
I'll bet this company finds a way to make this "new" product more expensive than regular burger.