Exactly. This is about protecting themselves from legal liability, not anything else. As the guy who hosts it is just a regular guy, not a corporation with limited liability/tons of startup dollarbucks, I don't begrudge him/them at all.
The Streisand effect is an unintended consequence of attempts to hide, remove, or censor information, where the effort instead backfires by increasing awareness of that information. It is named after American singer and actress Barbra Streisand, whose attempt to suppress the California Coastal Records Project's photograph of her cliff-top residence in Malibu, California, taken to document California coastal erosion, inadvertently drew greater attention to the photograph in 2003.
Yeah, I remember when this happened. Few people noticed or cared about the picture if her house until she tried to have it removed. Then it was suddenly on every blog site and news agency.
And the reason this isn't an example of that is that Lemmy.world isn't attempting to keep anyone from going to c/piracy, they just don't want the liability of having it on their servers. Anyone can very easily make another account and go there.