If this is true, you can look at it as Intel optimising their product range as best as they can.
Remember that 10-core is not a new offering. We already have 7900X Skylake-X for the HEDT platform. Intel's problem is that they were never prepared for the HEDT segment to approach the mainstream segment in pricing. Also, the workloads targeted by their respective platforms differ starkly. Their mainstream processors play games better, while their HEDT processors do better on parallel workloads.
This is how PC enthusiasts have been thinking about HEDT and mainstream — as two very different platforms.
But this is now changing, as I've speculated (
here). AMD's HEDT platform is becoming affordable, with pricing reaching down to the upper part of mainstream. Also, due to advances in boost technology, their 16-core HEDT processor has higher single-thread performance than their 8-core mainstream counterpart (in addition to more cache and memory bandwidth, 2950X has boost at 4.4 GHz, vs 2700X at 4.3 GHz), which means there is no longer a stark difference in gaming performance. Consequently, AMD now has a pretty continuous range of desktop offerings from 4-core budget mainstream to 32-core workstation-grade HEDT. Zen 2 will likely extend core counts and performance even further, driving down pricing for the last generation, and making the AMD HEDT platform even more tempting for PC enthusiasts.
This is what Intel is facing.
PS. Hence, I see no need for AMD to offer more than 8 cores for AM4. If, as expected, Zen 2 is competitive in single-thread performance, then max 8 cores plus iGPU is what makes sense in the mainstream (i.e. single CPU chiplet plus IO chiplet with iGPU). For anything beyond 8 cores, their HEDT platform is well positioned to compete.