Yes, but support in devices and cables is very limited.
But yes, support for the ethernet mode as far as I'm aware was never actually implemented in any devices that reached retail availability.
That could of course change. Could be even a nice feature for connecting your TV to the network via your multi media center, if the bandwidth is good.
https://www.techspot.com/news/113031-lg-alienware-monitors-c...
HDMI Ethernet is dead, it's never going to happen in consumer televisions because it has a hard conflict with a feature a lot of people actually use.
Proportion of non-HN users whose TVs don't connect to the internet? Negligible