The iPhone 8 is reportedly set to be replaced, not by iPhone 9, but iPhone SE according to 9to5Mac. The site has reportedly obtained inside information on the new phone and Apple has apparently already prepared to take orders for it already according to the report.
It will come in 64, 128 and 256 GB versions with an A13 processor, and you can already buy a screen protector for it here, on Apple's own website.
The iPhone SE version 2, is expected to be called iPhone SE 2020 and will be using the A13 processor from the iPhone 11, offering a considerable upgrade from the A11 Bionic chip in the iPhone 8. And yes, the iPhone SE 2020 is of course aimed at those iPhone 6 customers who have end-of-life devices due to Apples fantastic ability to not update the software of older models.
The colours will be white, black and red, and pricing earlier this year was reported to be $399 at the starting point.