I can't figure out an answer to why they'd do this. They're still supporting their custom Chromecast "receiver" app (for now?), which is a standard HTML app. But now they're detecting the Chromecast-capable device model, looking it up in an allowlist, then conditionally showing the device in the Netflix App's Cast UI.
This would mean if you have a new device and an old device in the same network the Netflix app might show only your old device! What?
Maybe I'm misunderstanding what they've done here?