Potentially fans with avid imaginations could invent pseudocanon and inject it into articles. Without listing sources there is no easy way to fact-check claims people insert. I believe we need to construct a [[template:fact]] association to "citation needed" to tag claims like that.
We also need a good way to have discussions on articles. I'm not sure comments cut it. Reading comments on character articles there's a bunch of complainy "I'm mad Proxima isn't royal" stuff cluttering up a space which should be about article improvement. There isn't a traditional forum either but it's the best alternative available.
We should be fastidiously removing any information which is not properly sourced and demoting it to a "potential information" subpage, subject for consideration if the person who added it can give some guideline as to where they found the information.