There are some communities where the vast majority of posts are by on or two users reposting news articles.
Sometimes they’ll summarize below, but they will almost never share their opinions on the article, or even just ask what others may think about in regards to this aspect or that aspect. So the entire feed is just URLs.
I would feel more engaged to comment on those posts, or even start a post in the community, when it doesn’t feel like a bunch of robots reposting the daily slop.
If the community is purely about news, sure. Most aren’t though, and I think in that case, the poster should always be the first ones to strike discussion.