the UN could potentially override the sovereignty of countries by pushing governments to adopt specific policies about what constitutes “criminal” information shared by citizens

The UN can't do that, but domestic politicians can comply and say they will enforce this shit. This is precisely why they keep trying to move the Overton window towards eliminating the first amendment.

Article 26, for example, of the draft document calls on countries to adopte [sic] ”legislative and other measures“ to criminalize individuals who engage in sharing content that promotes “subversive or armed activities directed towards the violent overthrow of the regime of another State.”

I guess Hillary Clinton bragging about the Arab Spring kind of put everyone on edge. The only time that I know of that social media was used to directly overthrow a foreign government was when the US did it to Libya and Egypt. It almost worked on Syria and it would have if Hillary had been elected.

https://archive.is/LzQjB

If you read this article about the Arab Spring, it hilariously posits the thesis that: "Foreign governments are bad and are scared of the US trying to 'promote democracy' in their system!"