IPv6 is silently gaining a lot of steam lately. Akamai reports[1] close to 50% from comcast and att over ipv6, and 80% from verizon, 72% from t-mobile. Reliance Jio, a new mobile carrier in India is doing 47%.

[1] https://www.akamai.com/us/en/our-thinking/state-of-the-inter... (click 'networks')