I get you, who knows how apple does this. I would think as soon as they ship, it's too late though. I am wondering though if Apple recompiled what we know now as the public build ahead of time for the pre-orders, then released today to everyone else. It would make sense since internally, they are way ahead but hard to say. Might have been a last minute build and restore phase as well.
The pegasus exploit was reported to Apple just under 2 weeks ago, it was likely fixed by the Friday. Pre orders started only a week later.
The logistics of it all, and how it’s worked in the past, with the amount of devices being made, and then shipped, they have to start loading iOS before the Pegasus exploit was fixed.
I would be extremely surprised if there wasn’t an update for the new phones for that.