Apple pretty much ALWAYS puts an older chip in their budget devices, which of course is understandable. It seems however a lot of people don’t expect this for some odd reason.
I’d expect an A11 chip in this device, but wouldn’t be too surprised if it gets and A10 like the “new” iPad.
The chances of it getting an A12 like the pricey X models is pretty much zero, as few would pay much more just to get an OLED screen.
Could also be that the new X models get FaceID gen 2, while this one get gen 1 from current X.
So in summary it will get a cheaper screen and shell, old internals, a single camera and possible old faceid.
I think it will still be the #1 selling iPhone, and Apple will as usual have great profit margins on it as all components have been produced for some time.
I don't really consider this a budget device at potentially $700-$800. This is closer to a replacement for the iPhone 8 which had the latest A11 chip when it was released. Maybe if they were trying to hit a $500 target price it would be justified, but at $700+ it will hopefully have the latest processor. Even the iPhone SE had the latest processor at the time of its launch.