There are advantages other than just the high resolution available under the UHD/4k umbrella (ITU-R BT.2020). The BT.2020 colorspace provides a wider color gamut, increased bit depths reduce color banding, supports 4:4:4 chroma sampling and up to 120Hz progressive frames are standardized.

Of course that doesn't mean Netflix can or will make use of any of them in their releases.