If you really want to flag disinformation, I'd be fine with some sort percentage reliability value or something along those lines, right next to the result. Preferably something that I can also order results by. Totally happy with a 'caveat emptor' clause regarding who comes up with those reliability values.
But down-ranking sites by default is not how this is supposed to work. "It's for a 'good cause'" is not the point. It's always going to be for a "good cause (TM)".
Besides, what's so bad about access to "disinformation"? I prefer being presented with bad arguments whose value I get to judge for myself, than being told I'm not getting all the arguments, only those whose value someone else decided on my behalf.