How would "algorithmic choice" laws/regulations impact ActivityPub?

Yesterday, Missouri's Attorney General announced plans to issue regulations
<https://ago.mo.gov/attorney-general-bailey-promulgates-regulation-securing-algorithmic-freedom-for-social-media-users/>
that would require social media platforms to “offer algorithmic choice” to
users. Clearly, it will take some time for this plan to be published,
studied, challenged in court, etc. It is also quite possible that the
regulations will be targeted to only the largest services (i.e. Twitter,
Facebook, etc.). Nonetheless, I think we should anticipate that the coming
to power of Trump and MAGA Republicans is likely to spawn many such
proposals in the coming years. Given this, I think it would be useful to at
least consider what impact such regulations would have on Social Media
systems that rely on ActivityPub and ActivityStreams.

My guess is that the position of the "ActivityPub" community would be that,
in a federated system composed of a multiplicity of independent
interoperating servers -- each having a potentially different moderation
approach, it is not necessary for each individual server to offer
algorithmic choice. Users are free to seek out and use a server whose
default "algorithm" addresses their needs. However, this position might not
be accepted as sufficient if the opinion is that the individual server, not
the federated system as a whole, is considered to be the regulated
"platform." The obvious question then becomes, what would need to be done
to  enable a federated service, even if very small on its own, to provide
compliant algorithmic choice?

Some will undoubtedly argue that the BlueSky support for a variety of
"labeling" services, when combined with user-selected client algorithms
capable of filtering, etc. based on labels, might be sufficient to provide
the necessary algorithmic choice. If such an approach is sufficient, then
one must ask if supporting it would require modification to the ActivityPub
protocols and schemas? (i.e. Would we need to add a "content label" item
that allows the annotation or labeling of posts, replies, collections,
etc.?)  Would a labeling service be able to rely on the existing
server-to-server protocol? Or, would something tailored more to the
specific requirements of labeling be necessary? Of course, it would be
useful to ask if there is a less cumbersome or otherwise superior method
for providing algorithmic choice. What do you think?

While the text of the plan isn't yet available, the AG's press release does
provide a sketch of what will eventually be published. See the list below
or read the full release
<https://ago.mo.gov/attorney-general-bailey-promulgates-regulation-securing-algorithmic-freedom-for-social-media-users/>
:

   1. "Users are provided with a choice screen upon account activation and
   at least every 6 months thereafter that gives them the opportunity to
   choose among competing content moderators;
   2. No algorithm selection is chosen by default;
   3. The choice screen does not favor the social media platform’s content
   moderator over those of third parties;
   4. When a user chooses a content moderator other than that provided by
   the social media platform, the social media platform permits that content
   moderator interoperable access to data on the platform in order to moderate
   what content is viewed by the user; and
   5. Except as expressly authorized below, the social media company does
   not moderate, censor, or suppress content on the social media platform such
   that a user is unable to view that content if their chosen content
   moderator would otherwise permit viewing that content."

bob wyman