This is fascinating and I have a bunch of questions, basically all centered around the fact that possession of the such content is outlawed. I don't exoect OP to know, but maybe someone else does:

Isn't it illegal to have a library of such content? Is there a legal carveout for that, like Coca Cola importing cocaine?

How is the library compiled, maintained, and added to?

Is the library specific to Discord or is it a shared library maintained by some centralized "authority" or developer? If it's specific to Discord then can we assume there are many different libraries of illegally produced and possessed content compiled and maintained by various social media companies? Who's got that job? Do they get therapy in their benefits package?