The processor used in the 2016 models is named SkyLake. From Wikipedia article of that name:
Sky Lake Known issues[edit]
Short loops with a specific combination of instruction use may cause unpredictable system behavior on CPUs with hyperthreading. A microcode update was issued to fix the issue.[68]
Skylake is vulnerable to Spectre attacks.[69] In fact, it is more vulnerable than other processors because it uses indirect branch speculation not just on indirect branches but also when the return prediction stack underflows.
The latency for the spinlock PAUSE instruction has been increased dramatically (from the usual 10 cycles to 141 cycles in Skylake), which can cause performance issues with older programs or libraries using pause instructions.[70] Intel documents the increased latency as a feature that improves power efficiency.[71]
The Vastly improved built-in Graphics capabilities of its replacement (used in 2017 MacBook Pro), named Kaby lake:
Kaby Lake features:
Kaby Lake features a new graphics architecture to improve performance in 3D graphics and 4K video playback.[7][28] It adds native HDCP 2.2 support,[29] along with fixed function decode of H.264 (AVC), HEVC Main and Main10/10-bit, and VP9 10-bit and 8-bit video.[27][30][31][32] Hardware encode is supported for H.264 (AVC), HEVC Main10/10-bit, and VP9 8-bit video. VP9 10-bit encode is not supported in hardware. Both OpenGL 4.6 and OpenCL 3.0 are now supported.[33]
Conclusion: this is not an arbitrary choice based on one factor, but a preponderance of accumulated issues with the older Sky lake features along with huge improvements, in exactly the areas the newest MacOS emphasizes, available in Kaby Lake.
