Though I honestly wish there was a more humane alternative to culling.
These industrial farms don't have room to spare for animals that aren't wanted.
I wish there was some kind of park or nature reserve or somewhere that they could be sent to live out their lives in peace instead of the culling. Or if such places already exist, laws that mandate that they be sent there.
Releasing large quantities of animals to nature is both anti-ecological and inhumane, as it results in destruction of that ecosystem, starvation, cannibalism, etc. Like the horrible aftermath of the cases when activists have "freed" animals from fur farms, resulting in them dying within weeks but also taking all the local wildlife (e.g. nesting birds) with them. You can successfully do a controlled release of a limited number of animals given proper preparation. But if we're talking about releasing large numbers quickly, culling is much more humane than that that.
Life on industrial farms sounds terrible, for sure, but death in nature is also terrible, to the point that I'm not sure it's a mercy to "set them free".