reading through this thread I still find it laughable that a spinner drive would even be considered when SSDs could be had for $20. yet knowing the apple under tim cook, I can totally see it happening. gotta wring every last penny out of the consumers after all.
Let's be fair here - $20 SSDs are not what Apple use when they put SSD into modern Macs - they are PCIe 4x NAND similar in spec to Samsung 970Pro costing at least double what these budget SSDs cost.
That's not to say that Apple shouldn't be considering putting 2.5" format SATA SSDs into their more modest offerings. Yes there would have to be a price uplift but how could they explain the performance difference between the SSD offerings on MBP and desktop models with Fusion?
This is a big stopping point for marketing so I'd say Apple should offer user upgradable 2.5" fusion drives in future headless desktop offerings for easy user upgrades. And obviously user replaceable RAM. To keep average selling prices up Apple should spec these models with Fusion Drive and 16Gb of RAM - higher average selling price means higher profit.
And the users who wish to replace non functioning hard drives and RAM with their own can then do so.