While it is theoretically possible to moderate to th point they are close to each-other, this is not the reality of any of the cases being discussed. Such draconian levels of moderation will kill any community that was not already a full echo chamber without diversity, and not in the "oh Facebook is an echo chamber" way but in a true, cult-like following fashion.
Affiliation vs Promotion vs Allow - Publishers have directly affiliated authors. Algorithms and manually curated sets within UGC are promotion. Most all other social postings are simply "allowing". These distinctions are important, and arguably each have different legislative implications.
On the scale of facebook or twitter, not really. You have enough users that every conceivable opinion is going to show up on your platform, and by boosting or suppressing those opinions, you have basically exactly the same amount of power and influence as a traditional publisher.
Strong disagree there. First, on either platform, you can go seek out every opinion under the sun, it's users that do their own content selection. Not to mention that there are top-level features that break any user-bubble like Twitter + Trending.
There's plenty of nuanced opinions on power/influence, but equal power/influence does not make them publishers, and I struggle to see how that relates to topics like moderation and liability. If these types of boosting/suppressing mechanisms are the policies actually in concern by people, this has nothing to do with all of the recent buzz/potential actions as any laws addressing that aren't going to get near that, only increase spam and abuse levels.
Are you going to make a law that me choosing the people I follow on Twitter is illegal?
Applying moderation before publication is active moderation, so everything that appears is approved by the "publisher." Applying moderation after publication is reactive moderation, so things the publisher disagrees with could get published.
It's like the difference between shooting someone to death and shooting a corpse.
If youtube only allowed centrist opinion vlogs and no other content, you might have a point. They are not even close to comparable to that in a practical world.