I am not sure if this is sarcasm or not but in case it is Not:

No it's not a solution, Netflix already heavily uses IPv6 and most sane v6 endpoints will not be NATed. Maybe they could use v6 Subnets as an Identifier but this would be wonky at best.

This would be a support ticket pandemonium since there are more than enough providers with dynamic IP adressing on v4 and v6.

But to be honest I think they might not need all that, more likely is they use some sort of device ID the modern Smart TVs already have Baked in or build some hash of their own with some device specific identifier (size, resolution, manufactuter, User Agent).

The article and information out there seems to imply they're primarily targeting TVs and devices that are used with TVs (SetTopBoxes, AppleTV, Firetv, Roku et al). So it makes no sense to use a device type unspecific Identifier like the IP in any way