So, some relatively unknown author is going to write follow-up novels for a series penned 50-some years ago... "If he had wanted to follow them up, he would have. The author's intentions need to be respected here." This coming from the same crowd that writes unauthorized fanfiction is quite ironic.
That's not the point. If the artists and companies holding copyright wanted to sue you as an individual for copying (or participating in copying their work), then they may do so. The fact that the operators of TPB were running a site that was relatively content agnostic means that the organizers had nothing to do with actually uploading torrents or seeding the data themselves. They are guilty by association, but they committed no crime.
Save yourself! Reboot in 5 seconds!