you can’t deny that a demand for meat influences the scale of meat production. Everyone in the production and consumption chain has blood on their hands.
"influences" is so weak that i am going to say that you meant "causes". is this a strawman? maybe. but if you're argument relies on the ambiguity of "influence" as opposed to the much stronger "cause" then you're not really saying anything of substance anyway.
so does the decision to eat meat cause meat production in the future? no. a thousand times no. first, and this should be all that needs to be said, farmers and abottoir workers are agents with free will, so their decisions cannot in any meaningful sense be said to be caused by anything except their own will. that should be the beginning and end of it, but consider this additional hypothetical:
if there are three blue pigs in the world, and i kill all three and send them to the butcher shop, when someone buys that pork or bacon or ham, how do we kill more blue pigs? it's impossible. so we can see that even if people lack free will and there is some economic theory that actually showed some causal link where consumption causes production (which is impossible), then we can see that consumption still can't actually cause later production in even this one case, but probably many others.