That's exactly what "reining in" looks like. Instead of being an alternative to, e.g. the New York Times and opposing the next Iraq war, social media just becomes yet another rah-rah cheerleading mouthpiece of whatever opinion the "serious people" hold.
I don't know if you consider Chomsky to be a "serious person", but Manufacturing Consent does go into how the people actually in charge of the government (professional civil servants, corporate lobbyists, etc) manage to make it seem as if their opinions are infallibly correct and countervailing opinions are thinly veiled crankery. What social media did (at least in its early days) was give everyone the ability to manufacture consent at a scale that previously was only the domain of the large media corporations. The establishment media is obviously threatened by this and are working to ensure that the new media follows the same guidelines as the old, even if that means censorship.
Of course, that's not how the establishment media phrases it (and probably not even how they believe it). They see it as "protecting" the people from unsavory "Russian fake news". In reality, though, that's just a lie they tell themselves and tell us to justify their continued hold on the ability to decide which opinions can be held by "right-thinking people". If they were truly interested in "the marketplace of ideas", they wouldn't be pushing so hard to make platforms as centralized, controllable and censorship friendly as they are.
The censorship debate is an indicator of game-rule collapse in social media. The platforms are reaching for top down control because they can't cook up a better way to reduce fraud and (let's call it) low-quality behavior. Ironically this method reduces the overall authenticity of the platforms and counteracts the intent of the censorship, and thus you get game-rule collapse.
I'm genuinely curious, do you have any more details or sources on this?
It was an interesting situation because in some ways, I prefer the transparency involved? But it's sort of like any sale of an account, even if temporary - it seems disingenuous by nature. Almost like how an MLM makes you sell to your friends.
How was the narrative controlled by the powerful before the internet became a part of everyday life? Specifically, how was the narrative controlled in the US in the decades before 1993?
I'm asking for recommendations of books written by historians, journalists and other serious people. (Understanding the situation decades ago is probably a lot easier than understanding the current situation -- partly because the powerful will take pains to hide their controlling actions from the public.)
In the US I get the general sense that politicians and holders of government offices have never been able to exert a lot of control of the narrative with the result that journalists and the prestigious universities have so much influence that they are best thought of as essentially part of the government.
That suggests that the efforts of the establishment to rein in the big social media companies will prove largely ineffective with the result that Facebook and Google will probably join the New York Times and Harvard as parts of the de facto governing structure of the US.
EDITED: changed "rein" to "rein in".