1. NotATeslaApp and Teslafi indicate there is no FSDb associated with this update. I'm going to assume that means that one stays with their existing version of FSDb because according to Teslafi, the vast majority of those receiving this update are coming from FSDb11.4.4 and since it looks like about 35% of the fleet (in the US only, Teslafi doesn't show installs elsewhere), we would have heard by now if installing this update removes FSDb.
2. GodElon knows.
3. There is no way. The cars are now on so many different streams that there is no way to tell when your car's configuration (based on features, location, paid FSD) will get the latest version. For instance, my car is not in the US and has FSD and still has functioning USS (but has had its radar software disabled.) Therefore, it would receive an update different to someone the US without USS or FSD. Tesla also will have a record of how long between being offered an update and downloading it and between downloading it and installing and I'm sure they take that into consideration as well. They know how many FSDb enabled miles I've driven and can thus prioritize me as worthy of an update or not if they choose.
Edited to add: Another confounding factor is what HW one's car has. Teslafi tracks installs on FSD enabled vehicles by their HW version (4, 3, 2.5, 2, 1, pre-autopilot) so that also allows tracking where one stands in the software offerings. I forgot HW version when I listed factors around which updates you'll be offered, when. In my signature you can see I have a very 'old' version of software, but in fact, it is the latest offered to me, and I'm riding around with the same software as 25% of the vehicles tracked by Teslafi that have HW3. The reason I'm not in with the 36.6% of those with 2023.44.1 is that I don't live in the US.
You'll find all sorts of instructions ranging from set the updates to advanced, do a reboot of the MCU, do a full shut down of your car (disconnect the 12V), do a less intrusive reboot of the car (by changing your tire settings.) But none have been conclusively shown to work.
(My update history shows a long time between discovery of an update and install. Partly due to the fact that I don't have Wifi at home and partly due to my refusing to install any new updates even if I accidentally download them (which happens if my car connects while visiting my sons.) At this point, I'm only accepting forced updates (if I don't connect to download and install, Tesla will push safety updates over wireless cell connection and trigger an install without asking for my permission (thankfully that happens in the middle of the night so the chance I'll get to my car and not be able to use it because it is updating is very slim.)
