I think you just have described Chromecast.Errrr, they already have that in Japan on fairly ancient (thick) LG flatscreens in cheap hotel rooms, maybe it's not the TV itself but the result is the same.
TV displays a WIFI QR code, you connect to it and then you can just airplay to it from your phone and use the internet on your phone as well. It's probably just a little router with airplay and hdmi in every room, but it looked very well integrated on the TV's hotel mode.