You seem to be having difficulty limiting both the study and my post to what was actually said, instead of expanding it to broader statements. That's what leads you to conclude the study is some sort of attack piece of Hannity/Fox, which is just silly.
That said, if you re-narrow the issue, then yes, if it could be shown that some liberal talking head took an especially skeptical view of Coronavirus, and that viewers of said talking head suffered negative consequences related to Coronavirus as compared to similar groups of media consumers, it would stand to reason that an argument could be made that said talking head bore some moral culpability.
It will be tough to make that argument, however. I'm guessing the real reason these researchers looked at Hannity is that he was an extreme outlier. Nobody displayed Covid skepticism, on either the right or the left, to the extent he did (at least among widely watched folks; I'm sure there are some lesser known extremists out there). So it might not be possible to find anyone similarly situated on the left, and it's quite possible that the closest the left comes isn't enough to lead to the kinds of effects that we see with Hannity. He could simply be a one-off, on account of how out there he was early on.
Plus, as I said above correlation does not prove causation. It's certainly possible that Hannity's viewers' poor performance with the virus is an artifact, and it's just dumb bad luck that it happened to them.
I guess it would be hard to find any liberal footage considering all CNN talked about was impeachment.