Unfortunately, this isn't true. It is not "inconsequential". Most people will read the headline/commentary and blindly trust it without reading the source mater

Unfortunately, this isn't true. It is not "inconsequential". Most people will read the headline/commentary and blindly trust it without reading the source material at all. This is a problem with the audience, yes, but it's also a problem with the organizations that take advantage of the audience. But even amongst those that do still read the source material, if they read the commentary beforehand they are still likely to have their perception influenced a certain way, even if only subconsciously. Psychological priming is a thing.