Now that BM is public, I assume we can relatively easily get answers to information about quantities sold. I would be interested in seeing a Fermi estimate of suffering-days they have averted or something similar. (A simple model is something like: quantity sold times fraction of customers that would have purchased the corresponding animal product times days of suffering per animal product.)
I could still see a sizable impact coming from the consumer skipping a meal of chicken that they otherwise would have ate and substituting it with beyond meat. It doesn't have to be an exact substitute.