Here’s what Netflix said:
With our latest 5.0 release, we now fully rely on the Widevine DRM provided by Google; therefore, many devices that are not Google-certified or have been altered will no longer work with our latest app and those users will no longer see the Netflix app in the Play Store.
The crackdown has mostly to do with digital rights management, and Google’s Widevine DRM protocol in version 5.0. Netflix is taking measures on piracy from its video service, which no doubt has increased since they started offering downloads of certain titles for offline viewing.
While the loss of the Netflix app is a bummer for rooted Android users including developers who alter the OS for professional reasons, Netflix has got to protect their content from being shared without license.