Nobody knows and Tesla isn't communicating much. One would hope that if they really knew they were done adding "early" testers for months (or forever), they would've just removed the button, or had their servers kick people back out of the queue after pushing it.
The most charitable view is that they've been intending to add new entrants from the queue for all these months, but have kept repeatedly missing their own targets for when they'll have a stable-enough release for it to make sense (which, after this many months, would imply they're performing pretty terribly against their own expectations and estimations, so it's still not a very positive view in some sense). The least charitable view would be that they've known they have "enough" US testers for now since ~Xmas and they've just not put in any effort to disable the button/queue in the US and/or communicate about it (which is pretty infuriating to those stressing over safety scores right now).
The most recent Elon tweet/announce activity (closest thing we have to Tesla official comms) related to all of this has been basically 3 interesting things:
1. Most times, in recent months, if someone asked him when/if new US entrants in the queue will get in, he's ignored the question and said nothing.
2. In mid-March, he directly said "If this version performs well, we can probably lower min safety score to 95" in response to a tweet which said: "Maybe elonMusk will expand the Beta program w/ this release. The peasants are getting restless", which had quoted the 10.11 release notes as the version referred to by "this" in both cases.
3. At the Cyber Rodeo event, he declared (in speech) that FSD Beta would go out to all FSD customers "this year" (presumably meaning it's still an opt-in beta, but everyone can just click the button and read a disclaimer and get in?).
The other interesting data point is that an initial batch of cars in Canada have gotten in from the queue while we've been waiting in the US. This implies that the current releases aren't so bad on quality that they're afraid to inflict them on new users, or they probably would've delayed that as well.
So, the murky reality underneath all of this that we have no direct knowledge of, plus all the ways in which various things could evolve or go off-track in the near future, leave a lot of room for pointless guessing! My personal bets for the most-likely outcomes at this point are:
1. Eventually a 10.12.x goes to new US queue entrants sometime in the next ~6-8 weeks, starting with most/all existing testers, then new entrants with ~98+ scores, and eventually moving all the way down to 95s (or not, who knows), possibly over the course of a few of bugfix point releases. (and then who knows after that how things go for wide release of a later version to all FSD customers). This could even still happen with a 10.11.x release, although it seems less likely with every passing day. It would mean either 10.11.3 moving to being based on 2022.8 or 2022.12, or an (unlikely, we're guessing) backwards push for a bunch of cars that are already past 2022.4. They did move ~all existing testers up to 10.11.2, so that's something.
2. They're confident enough in the nearness of their release to "all FSD customers" that they don't bother with any further pushes from the safety score queue in the US and make us wait for that, because they think it will be by ~Summer anyways (and then they'll miss their targets again and who knows when it will actually happen, maybe in 2023). We keep playing safety score games the whole time and never hear anything definitive and keep getting more frustrated the whole time.
3. Regulators and lawyers manage to derail everything before any of this happens and all plans go out the window.