Also, early indications seem like the -AP series are not going to be used by many vendors. Part of the reason is that basically Intel is providing nearly everything, so they are a pseudo-vendor for -AP platforms. Other than putting your company's sticker on the boxes, there's little way to differentiate. Maybe the bigger reason is that besides some really needing density for #1 linpack competitions, other platforms(including AMD's) are more attractive.
It may eventually sell more than Xeon Phi as successors are introduced, but Cascade Lake-AP doesn't seem to be it. Perhaps Icelake-AP with HBM2 memory?