"Dark Patterns are tricks used in websites and apps that make you do things that you didn't mean to, like buying or signing up for something."

So... it's a "dark pattern" to give you access to some articles for free and then, should you like them and want to read more, ask you to pay for them?

IDK, but that seems pretty straightforward to me.

I'd say it is a dark pattern to fill the screen with annoying banners asking me to sign up when I just want to read an article.

Dark patterns are tricks, like making you click on something that you thought did one thing but does something else. Asking you to sign in/up is hardly a dark pattern.

And I've yet to see Medium "fill the screen" with annoying banners. In fact, from what I've just seen, Medium just displayed a web page with the article's bottom half telling you you've read all of your free articles and asking you to sign up.

Too much hyperbole on the internet these days...