This ruling only applies to copyrighted content that is legally and publicly available. Linking to content that is behind e.g. a paywall would constitute a copyright-infringement.
Wait, how can it be a problem to link to content *behind* a paywall. Either the person clicking the link will not be able to get to the link as the content is behind a paywall and they haven't paid, or, they have paid, have rights to the content, and can get to it by following the link. Is there some other possibility?
all the best,