I've never been involved with implementing large-scale moderation or content controls, but it seems pretty standard that underlying automated rules aren't generally public, and I've always assumed this is because there's a kind of necessary "security through obscurity" aspect to them. E.g., publish a word blocklist and people can easily find how to express problematic things using words that aren't on the list. Things like shadowbans exist for the same purpose; if you make it clear where the limits are then people will quickly get around them.

I know this is frustrating, we just literally don't seem to have better approaches at this time. But if someone can point to open approaches that work at scale, that would be a great start...