I hope that you’re wrong about those specs, particularly the A12. What’s the point of having a event for a device that has virtually the same specs as its 18 month old predecessor? That would make this Air entirely a cosmetic upgrade.
Not that there isn’t precedent for that through. 7th gen iPad has the same A10 as the 6th gen (but at least had a RAM upgrade), and the Mini 3 had exactly the same specs as the Mini 2. But those devices are/were on a 12 month update cycle at the time.
The thing is they can't really put an up to date and powerful processor in the new Air 4, the iPad Pro 11" would then be pointless. I saw on Twitter that Even Blass has said the Air will get an A14 chip, the guy is usually very accurate but i don't think he's right about that! Putting an A14 into the Air would make it more powerful than the current iPad Pro, unless they are also updating the Pro at the same time (which i really doubt since it was updated a few months back).
I think the design of the Air will get the 2018 Pro design (thinner bezels and removal of the home button) the Touch ID will either be in the display or on one of the buttons. No Promotion display, LIDAR or anything like that.
It will be interesting to see what Apple do with the Air 4. Only a few more hours until we find out