They are entertainers and news readers. Their opinions mean squat.
They're employees who will do what they're told.
If their opinions mean squat, why do people get upset if they color outside the lines?
In a defamation suit being decided in a court of law, their opinions indeed mean squat—more than squat.
In order to prove “defamation” (as a legal term) one must prove “actual malice,” and one of the things that determines “actual malice” (as a legal term) is if said statement(s) were published or broadcast
“with knowledge that it was false or with reckless disregard of whether it was false or not.” New York Times Co. v. Sullivan.
For multiple Fox employees to broadcast or publish statements about Dominion while questioning the veracity of those statements will make a difference in whether or not Dominion has a case.