Not at all as far as I’m aware. There’s no mention of paywalled content, or archive links, anywhere in the TOS or in any other guideline or policy. I’d guess that it would be against rules to post an article or content that must be explicitly purchased, with a subscription, for example. As it would count as linking to piracy. But in this specific case, where the article is walled by making an account, it’s fine in my opinion. It’s a gray area in the worst case. This is why most communities encourage posters to post a freely available article when posting news. And if it’s something inaccessible without paying for it, just don’t post it at all, or make a text post or post an article about the thing. I mean, piped links are encouraged, and that’s a similar thing.