One of the statements that keeps coming up about characters is that a "misinformation campaign" or a "campaign to misinform" was used to hide the facts about that character. At it's heart, that's correct in a small way, but the way those phrases are being used takes it a lot further to where it's being misused to justify what is being said.
The defintion of "misinform" is pretty simple: "to give false or misleading information to". Where that's correct is that a movie studio, writer, director, actor and advertising department will never come right out and say "this is exactly who this character is" before the movie premieres or the TV episode is broadcast. They'll give a hint to get your interest, but they won't say things that give you the whole picture. If they did, then there's less reason for you to watch the movie or episode, and that means less money in their pocket.
Wikipedia has a page on misinformation, which says it's "false or inaccurate information that is spread unintentionally". In other words, the people saying something don't know that what they're saying is wrong.
If that comes from any of those five sources, that's bad. It means the people involved in making or advertising the movie or episode don't know it well enough to be able to tell when they're saying something wrong.
That's rarely going to be the case. An occasional mistake is no big deal, but claiming these people are misinforming others is a big deal. That's being done by saying there's a campaign to do this.
A campaign is a series of deliberate steps to achieve a specific goal. In this context, the people on this wiki are saying that when information was released about the movie or episode, there was a deliberate attempt by the people making it to hide how much of an antagonist a character is. That information would have been in a movie trailer, commercial, press release, article or interview.
Again, that's rarely the case. It costs time and money to create an advertisement. You've got a limited number of time at a large amount of dollars per second to get a message across. You need to pass along details about the world of the movie or episode, who the characters are and hints about what will happen in it. If you spend a portion of that trying to say "we're going to pretend this antagonist is more important than they really are so you won't know who the real antagonist is", that's time and money not being spent on everything else you need to do in that limited time. Likewise, a press release, article or interview is not going to focus on an antagonist because there is so much more that needs to be covered.
Where saying there is a "misinformation campaign" or a "campaign to misinform" becomes really bad is when you put those two definitions together. Both say "we're going to make the effort to deliberately tell you things about this character, but we don't know what we're saying is wrong".
Think about that.
If there really is a "misinformation campaign" or a "campaign to misinform" about a character, it means the people involved in this movie or episode are lying to us and they don't realize it. Or worse, they're incompetent and stupid.
I don't think anyone believes those people are liars, incompetent or stupid. They're just trying to justify their opinion about the character and to provide an explanation as to why someone else thinks the character is a different kind of antagonist. But in that way, trying to say there is a misinformation campaign becomes a misinformation campaign by them.
No proof is ever given that there is an official source to back up what they are saying. It's an opinion that they're trying to turn into fact. If you want to try and say there is a campaign that involves misinformation, you have to provide a source. If you don't, that's false information on your part. And if you keep adding false information, you become the liar and/or it becomes vandalism. Both then need to be removed from the wiki.