Time will tell. But 2024.3.25 was given to FSD users as well as to testers. The testers were held till just before noon on 6/11, when all 5,000 or so started getting moved to 14.9. Prior to that, many more already were on 14.9 and thousands of those had already moved on to 2024.20.1.
It is hard to tell from the TeslaFi site who is using FSD, or who is in the tester group. It appears that some FSD users have recently been getting the same updates as testers, but since everyone is currently being moved to the same FSD version, 12.3.6 now, we all appear to be in the same boat. Even the next release may not distinguish testers from all FSD users.
For all I know, the tester group may have been dissolved and merged into the FSD branch. But if so, why are we still on 14.9? We'll see...