They do, although the reason is exactly opposite to why it breaks down the protein.
The mostly citric acid in the tomato does help break down the protein by the denaturing process but it does that by lowering the pH environment making it acidic. Baking soda raises the pH environment making it more alkaline which makes the meat more tender but I never use baking soda for velveting and use cornstarch, egg white, shaoxing wine and soy sauce and haven't actually seen baking soda used, but I'm sure some do.
But I can leave chicken if it hasn't been overcooked in a tomato sauce for days without it basically breaking up or disappearing and like I said that was from overcooking and moving the ingredients around that eventually breaks up the protein into small and smaller pieces and eventually your asking yourself where did the chicken go, lol