@piggo I understand it so that they are not only blocking links to other social networks, but also to aggregators which make it easy to "mention" twitter+other social networks alongside. The paranoia goes quite deep in this step.
@piggo @fribbledom @FailForward It's commonly used by all forms of content creators to display their Patreon, Amazon wishlist, "buy a coffee" things, OF, whatever. It's hugely pervasive.