You still need to sign up to/log into Threads (via Instagram) to have a Threads account or be active on there though, so what makes it theoretical? If they counted all Instagram accounts as Threads accounts it'd instantly be in the billions surely.

This will be referring to recently introduced laws essentially banning all/any abortion to be carried out (in some states even in extreme cases like rape/incest, or to save the life of the mother), but outside of that an illegal abortion might be due to it being done later in the pregancy than is legal, or without following required processes e.g. requirements to get scans first, alert the father, or have a consultation (most of which are often just traumatising anti-choice measures). Also as you say, using an unlicensed practitioner or unsafe method, yeah. Which aside from money, is sometimes due to fears of repercussion from their community or partner about either the pregancy or getting an abortion, so they seek back-door options or try to do it themselves without proper care.

Yet another reason to be annoyed about Brexit

If you federate with Threads, dont Meta have that federated user and content data cached on their servers? Producing content outside of Threads and posting it to Threads still gives them content, and information about you. Much like how people without Facebook accounts still have shadow profiles from being featured in Facebook users' pictures and posts. The only solution seems to be (though maybe I misunderstand) not to federate or engage with Threads servers. This would be too philosophical a point for the vast majority of Internet, and especially ex-Twitter, users. Mastodon instances would have to explicitly defederate which could kill their userbase if the traffic flows to Threads, which it did in a matter of hours.

I didn't see this until just now! No notification outside of the app, my inbox inside the app got a (1) unread icon when I refreshed earlier.

Notifications have been very spotty for me on Jerboa (not tried the others) but they are implemented. Just not always effectual for some reason.