Many people misunderstand the reason for the existence of iPhone SE in the first place. The fact that it was small was never the point, the low cost was. The iPhone 5S chassis was the most cost effective way of achieving the desired cost at the desired profit margin. Sure, this was very welcome by the people who wanted up-to-date spec in a small form factor, but this was a coincidence.
In the same way, iPhone 8 chassis will be the most cost effective way of achieving a similar brief currently, which is why MCK's supply chain intelligence reflects this.
I realize that this is quite disappointing to users who want a small phone, however judging by the portfolio of the top manufacturers there doesn't seem to be a case for small phones with premium specs currently.