Most likely the human consumed meat amounts will change very little. But let's say for some reason 50% of humans suddenly started only eating Impossible Foods style meat - I would imagine that along with that sea change would be pet food. (And when I say suddenly I would say expect at least 25 years - 50 years)

That's interesting. I wonder if that is in fact the case. There could also be a surplus of meat waste in the meat industry, some of which could go to pet food if the overall production decreased.

I admittedly know very little about the meat industry.