This message was posted on behalf of Intel Corporation
At this stage, I do not have an official word for this type of compatibility information.
The list of tested peripherals has not been updated yet, please take a look at this site for more information: http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-nuc-kits/000016218.html
I would recommend waiting for an official information word about this type of compatibility.
The form factor for SSD 600p Series is 22x80mm.
NUC6ixSYH clearly stated that it support 42 or 80mm M.2 SSD slot.
However you indicted its not compatible.