I wound up just commenting out those specific lines for now and I'm still seeing baby animals spawn in the server so it doesn't seem to have hurt anything.
Yeah. it won't. Basically what is happening is the way the code is written is a little future proof. I am trying to append the animal to a proper group, and the game is not finding what I am searching for. Since what is produced is just a warning and not an actual error, I didn't really worry about it.