It doesn't need it, I think it was just something that was interesting to have. I have not seen anyone saying there were any plans to make it non-optional, and that would probably not make sense to do that, because there are a lot of other network daemons that people use with systemd.
I presume because they are using a mono-repo for all the related projects. A GitHub repository doesn’t have to map to exactly one output. Just because the code is in an adjacent folder doesn’t mean that it’s used in all the targets.
If it became non-optional, then sure you can include the LOC then.