As I expected, my analysis indicates the impact of chicken welfare reforms is driven by effects on wild animals. I estimate broiler welfare and cage-free corporate campaigns benefit soil animals 444 and 28.2 times as much as they benefit chickens. I think the same applies to any intervention targeting vertebrates which changes the consumption of feed or food, especially if it mainly aims to increase/​decrease positive/​negative vertebrate-years.
My best guess is that decreasing the consumption of animal-based foods is harmful. I estimate School Plates in 2023, and Veganuary in 2024 harmed soil animals 5.42 k and 3.58 k times as much as they benefited farmed animals. Moreover, I guess arguments for decreasing the consumption of animal-based foods based on environmental considerations, and animal rights harm wild animals longterm due to encouraging wilderness preservation. In any case, I expect the nearterm effects to be the driver of the overall impact. So I would still consider decreasing the consumption of animal-based foods harmful even if it helped wild animals longterm.
Here is a related post I have just published.