That's just some users though, and I'm 99% sure they don't want others to see it, because they believe knowing about it might damage their political side. I'm sure they have good intentions and believe that the end justifies the means and if suppression of truth is required to let the good guys win, then so be it.
Of course, everybody generally thinks they are the good guys, and once you're going down the road of "everything is allowed because my goals are good", you're not going to stop until somebody else stops you.
You could say that about lots of news that FB and Twitter allow. If FB and Twitter are strictly blocking unverified news then they would have also blocked things like the NYT tax return story. You also wade into some hairy territory of who is verifying news, and why.
Facebook and Twitter are effectively acting as editors for select news organizations.
Of course, everybody generally thinks they are the good guys, and once you're going down the road of "everything is allowed because my goals are good", you're not going to stop until somebody else stops you.