NUC6i5SYH supports NVMe Gen 3 (please refer to the Expansions Options in the Specification Data).
In addition please see the list of validated M.2 PCIe drivers. FYI, the Samsung 980 Pro SSD has Gen 4 M.2 interface. Probably it will work in your NUC (since is backwards-compatible with PCIe 3.0). However you will not reach the NVMe Gen4 speed. So, if you don't have a PCIe 4.0-compliant system, you're better off going with a cheaper PCIe 3.0 SSD that can reach the same speed.
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Due to this product being discontinued, Intel Customer Service no longer supports inquiries for it, I am glad to see that fellow community members have the knowledge and they jumped in and helped. You may also find the Discontinued Products website (https://www.intel.com/content/www/us/en/support/discontinued-products.html) website helpful to address your request.
You can get the specifications and verify this product's discontinuance status at the Intel® Product Specifications website > Product Status > "Discontinued". https://ark.intel.com/
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Intel Customer Support Technician