You can't double the framerate from 30 to 60 anyways, because the signal is output at 60hz. Best you could do is double it to 120 and some manufacturers even claim 200hz or 300hz but I doubt the panels are actually capable of displaying those refresh rates so I'm not sure where they're getting those numbers from.
I am sure it can, videos in 24 fps or 30 fps can have motion interpolated to 60 fps on those new TV. Games in 30 fps should look like 60 fps, it won't look artificial like movies - since we play games in 60 fps. For film, it just look 'cheap', like TV news.
If anyone is interested, there's a freeware called Splash Pro that can playback your 24/25/30 fps video in 60 fps or more. SVP used to be free, but now it's commercial. As far as I know this is the best and only free one available:
https://mirillis.com/free-hd-video-player