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.)
Ever so rough fermi: Beyond's revenue was around $100 million - they sell their products at $1 and save an animal for every 100 products sold, then they save 1 million animals a year. Increasing their revenue by 1% through a grant or unpaid internship would save 10k animals.
But if the market is efficient, the counterfactual impact of for-profit clean meat companies is converging towards zero.
More basic clean meat R&D might be more undersupplied by the market.
According to their S-1, in 2018 they sold a total of 11.8M pounds of their "fresh" products. A large majority of this was the Beyond Burger.
Given that 93% of retail consumers that purchased the Beyond Burger also purchased animal meat, I think we can assume a pretty high rate of counterfactual replacement of beef - let's say 75%.
That's a total of 8.9M pounds of beef displaced. Assuming a cow yields 490 pounds of beef, that's around 18 thousand cows spared in 2018. This is impressive!
However, I agree with zdgroff in that the majority of the impact of Beyond Meat is the expected future impact when they focus more on chicken, and in legitimizing the plant-based meat industry.