Apple News and the Stocks app do exactly this. It's happy to clutter up your news feed with subscriber-only articles, despite knowing that you don't have a subscription. Predictably there's no option to not show subscriber-only articles. So there was a workaround: you can block individual news providers, so you can block all of the subscriber-only ones.

But now when you block one, it says "If you block XYZ, News will stop showing stories from this channel, except when selected by the Apple News editors".

Ridiculous. If I go to the trouble of blocking a site, that means I don't want to see anything from them, ever.