I think they buried the lede here! By combining the ability to determine dispersion in the signal path and now pinpointing the source, they recalculated the percentage of matter vs dark matter.
Dark matter makes up 95% of the universe now?!? As the article states, this is indeed mind boggling. We're missing a BIG piece of our understanding about the nature of the universe itself.
I think you misunderstood. 95% of the universe is not-ordinary-matter, which is split between 70% dark energy and 25% dark matter. _This model has been widely held for years._
This same model suggests that there should be 5% ordinary matter, but until now we have only observed half of that 5%. This new FMB observation shows the full 5% for the first time, bringing our observed data to better alignment with the model.
The article was very poorly worded. As @infogulch noted, the 5% is of the total energy content of the universe, not the "matter" content. So that's been known.
But what seems to be new is that of that 5% of normal (baryonic) matter, we've only been able to account for about half of it (stars, gas in galaxies). These FRB observations claim to have found evidence for the other half of the "missing baryons", likely in hot gas between galaxies.
Dark matter makes up 95% of the universe now?!? As the article states, this is indeed mind boggling. We're missing a BIG piece of our understanding about the nature of the universe itself.