Can we recognise something really rather important about what an opinion is?
Here's a typical definition:
a view or judgement formed about something, not necessarily based on fact or knowledge.
You might expect that I want to highlight "not necessarily based on fact or knowledge", but I don't. Note the word "formed". The majority of people haven't formed opinions, they're parroting them. So they're not their opinions and that makes them propaganda.
Another definition reads like this:
An opinion is a judgement, viewpoint, or statement that is not conclusive, rather than facts, which are true statements.
Note the phrase "not conclusive". Individuals that hold an opinion that won't be changed don't have an opinion, they've been indoctrinated.
Fox News is a PsyOp. This, of course, is my (actually meets the standard of the defintion) opinion.