The troubling aspect is it comes with some level of authority backing the claims. There are consequences for not aligning with the positions of the claims.
No, I'm not asserting that view. However, what you are stating I think is the viewpoint of most people. They will accept the claim as valid.
Do you think that most people think that whether a claim is true depends on Facebook's stance on that claim? That would be extremely shocking to me. My impressions is the opposite: that there is mainstream repulsion to Facebook (and Twitter, etc.) being so bold as to take any stance on factual issues.
However, it does reinforce confirmation bias. Those that align with Facebook's viewpoint will be less likely to listen to other user's opposing viewpoints as the feel emboldened that they viewpoint has some official support.
So I think it has an indirect effect in that it weakens user to user influence.
The problem is the poorly-considered but extremely widespread epistemology that goes something like "whether a claim is true depends on how convinced certain people are of that claim."
> Once you create a fact checking entity, it will decide for itself what are object truths.
No, it will just make claims, which may be true or false. There's nothing mysterious or troubling about this. They're not "deciding" what's true.