For those worried about blocking certain viewpoints, it’s important to note that the sources on the list aren’t there for the unpopularity of their opinions, but rather the frequent publication of misinformation. For instance, Fox News, despite its frequent bias, is not one of the publications on the list.
As others have noted, the list can essentially be summarized as state-sponsored, tabloid, and extremist media outlets that, intentionally or not, have editing standards that result in misinformation on a regular basis.
Note that the sources on the list are there due to the frequent publication of misinformation, rather than their bias alone.
As others have noted, the list can essentially be broken down into three categories: state-sponsored media outlets, clickbait-style tabloids, and extremist media outlets.
The categories themselves are just a means of summarizing what’s on the list though, as outlets in those categories that maintain editorial standards that disallow misinformation wouldn’t qualify for inclusion on the list.