This has nothing to do with dark matter, it's about the missing baryonic matter. And this result just confirms what most people thought anyway, but it's still rather important because it's a very solid result so we don't need to call it "missing matter" anymore.

This study accounts for missing ordinary matter, not dark matter. The linked article makes this clear in the first paragraph. Sometimes I wonder if the first commenters (and often top commenters) on HN read the article at all or just respond based on the headline, because these comments often seem barely related to the actual article content.

No.