I've been looking all over, but I can't find any definitive proof that they are compatible. Supposedly, the predecessor VII GENE is compatible, but Intel has not (to my knowledge) updated their compatibility list for Z170 chipset motherboards.
As you mentioned, the list of compatible motherboards has not been updated to include boards based on the Intel® Z170 chipset.
The documentation of the motherboard indicates that it meets the requirements to boot from the Intel® SSD 750 Series, actually many users have reported that they are able to boot from their 750 with Z170 based motherboards, even low end models from different vendors (including Asus).
You might want to check with the http://www.intel.com/support/oems.htm Computer Manufacturer Support if they have tested the Intel® SSD 750 with this motherboard. Also, here are some reference documents about this topic:
http://www.intel.com/support/ssdc/hpssd/ssd-750/sb/CS-035496.htm Intel® SSD 750 Series — Before You Buy
http://www.intel.com/support/ssdc/hpssd/ssd-750/sb/CS-035483.htm Intel® SSD 750 Series — Frequently Asked Questions (FAQ)
http://www.intel.com/support/ssdc/hpssd/sb/CS-035481.htm Intel® High Performance Solid-State Drives — Booting an NVMe* PCI Express* Solid State Drive