Analysts weren't really taking a risk when they made this prediction were they, considering the iPhone 8 will step down a tier to make way for the 2018 8S (or whatever it will be called).
I'm not an analyst, but I predict the 8 won't drop down a tier. I predict the 8S will be released in three sizes of full-screen AMOLED display devices as rumored. The second-tier phones in 2018 will be the 7S, 7S+, and SE with LCD displays. The 8 will just disappear as a one-year model.
Apple is going to milk AMOLED as a premium-only feature for as long as it can, and a mix of $1,000 8S and $900 8 devices don't make sense. Apple needs something in the $600 range which is where the 7S would fit in.
For 2019 I can see Apple finally cutting the prices on the AMOLED phones and dropping LCD models altogether.