I can definitely picture a piece of content that's been scrubbed from everywhere except old copies of LLMs in which it still exists in a lossy form, with people trying to extract it from those old copies with the help of newer models. Private trackers have thrived for decades and will continue to do so because they allow a community to foster around a shared purpose (pardon the pun).

Although that being said, i doubt i would go through the trouble of signing up just for this purpose, personally.