Looks like Kaby Lake will likely not be released for the 15" rMBP if this report is of any indication
http://www.notebookcheck.net/Intel-Another-detailed-CPU-roadmap-leak-2017-2018.173996.0.html
Iris Pro will not be available for Quad Core 47 watt CPUs, only GT2 Intel graphics so looks like Apple will stick with Skylake or integrate AMD GPU's in all models. Don't see Apple ditching Intel graphics after heavily utilizing in all their previous models.
Hopefully Apple nails the next MBP release, because it sounds like it will be a while before they release updates after this year. The article you site states, "According to [Intel's] roadmap, Skylake will continue to be in the market in one segment. High-End Quad-Core CPUs with Iris Pro GPUs like the Core i7-6970HQ will stay in the market till the released of Coffee Lake in 2018."
You heard it here first. If Apple insists on its love affair with Iris Pro GPUs, there will be: (1) No Kaby Lake 15" MBPs and (2) No updates to the 15" MBP after this October until 2018.