The way I understand it, the software update is not supposed to fix an existing cam phaser issue, it is supposed to prevent the issue from arising if it has not already.
(Long-ish post, sorry)
Firstly, as a recap, there are two common rattles at start-up, one is cam phasers, the other is the turbo wastegate.
1) The cam phaser rattle is a harsh buzz immediately upon cold start and it lasts for 2-3 seconds. Then it is over and you won't hear it again until the next cold start.
2) The turbo wastegate rattle is a softer, rapid ticking sound. It occurs immediately upon cold start but persists for about 90-120 seconds until the components warm up a bit. Sometimes you can also hear it idling in a drive-thru or other instance in which your engine noises are being reflected back at you by a wall.
You might have one, or the other, or both, or neither. They are separate issues.
The software update is only designed to address #1 (the cam phaser buzz), NOT the soft rattle you get from the wastegate. The wastegate rattle is an issue, but not one that Ford has really yet addressed. Some users have successfully managed to convince their dealer to replace some turbo components and have had limited success once they have new parts.
The software update, as I mentioned above, is not designed to fix a cam phaser buzz/rattle once you already have it. From what I understand, the cam phasers start rattling as a result of insufficient oil pressure upon start over time. If the engine cranked a few times it would allow the oil pressure to build before combustion, but these engines don't come from the factory programmed that way; they come programmed to fire up almost immediately when you push the "start" button. The software update changes that...once the new software is in, it forces the engine to crank a few times before combustion thereby building that necessary pressure and lubing the components. But once you have the rattle, the "damage" is done; the phasers are already out of sync, or damaged, or whatever, and additional cranking programmed by the updated software won't repair them.
(Related: if you hold the brake pedal and the gas pedal before/while pressing the "start" button, you can force the engine to crank until you release the brake pedal. Essentially you are manually doing the same thing the software update is doing.)
What the update WILL do, is prevent the cam phaser issue from manifesting. If you get the update before you have a cam phaser problem, the increased cranking and increased oil pressure will allow the parts to get sufficiently lubed before combustion and will (theoretically) prevent the problem.
So, folks that already have the 2-3 second buzz at startup who get this software update looking for a fix are going to be disappointed. It's not supposed to fix the problem, it's supposed to prevent it.
And again, NONE of this will do anything about your turbo wastegate rattle. That is a mechanical issue that is not addressable by a software update.
To recap:
1) turbo wastegate rattle - annoying but not fixed by software update
2) cam phaser buzz - theoretically PREVENTED by software update, NOT FIXED by software update
(as to what effect the software has on your transmission, I have no idea)
