I would not be surprised if we did still eat them, so long as we were removed from their suffering. We ignore the suffering of talking human beings every day, I don’t see why we’d suddenly start taking notice of animal suffering if animals could talk.
The people we willingly exploit for frivolous products like chocolate and coffee can talk. The people in poor nations we test our products on can talk, and the majority of us don’t care enough to stop the suffering there. If chickens could scream for help, we’d most likely just make sure we never went close enough to them to be guilted.
And something I’ve just thought of… We’ve found that apes can be taught to speak using sign language. In some cases it might be simple mimicry, but in other cases the apes have learned to make sentences, apply meaning to their signed words, ask questions, and figure out concepts that are somewhat abstract in nature. Last time I checked, we were still testing products and procedures on apes, which can cause great pain and suffering. We’re still clearing their land to make furniture and to get palm oil for our processed foods, and people are still hunting them.
Long story short, it’s pretty evident that most people wouldn’t give a damn if animals could talk – they’d keep exploiting them regardless.