That's a bit of an oxymoron in itself. This early in the game most of the rumours are from guesses regardless of their origin.
So called experts like he who shall not be named, you can guess who I mean, make claims based on at best vague supply chain rumours. They get some things right but normally not that much more than the blindingly obvious things we can guess ourselves.
With Apples penchant for having more than one set of parts, or device, floating around the supply chain to throw them off the scent when there's something big in the pipeline it's just too early to tell what is most likely.
So in the meantime, we might as well have some fun baking up our own iPhone 8, chances are we'll come up with about the same proportion of correct guesses as the *ahem expert analysts