Court cases, and documents submitted in them are, unless the judge decides otherwise, public information.

In addition to sibling, FOIA is only for the government (and probably work that government contractors do that's related to their contract, which this isn't).

The contents of any evidence brought forward as part of the case by either side as public information that is part of the record of the court case.

This includes information that is submitted voluntarily or extracted via a discovery request. (Not everything you find is public only what you submit as evidence)

Note you can avoid things becoming public but you need a decent reason to "I don't want to share that" isn't enough. It looks like this document was partially redacted for instance.

To your original question courts make the proceedings "public" although there is a process for getting a copy. Not so much a "can you get this" more of a "we don't upload to a server and let web crawlers index everything".

The other commenter is correct but largely not FOIA, which applies to federal, state, and other public authorities.