I'm not convinced any of this would have mass appeal though (whatever my preference for Mistborn over Stormlight might be
).
Game of Thrones is the only highly successful fantasy TV show to date. The problem with trying to replicate that with other fantasy series is that GoT is mediocre fantasy mixed with broad, high quality political intrigue and most of the focus is on the intrigue and not the fantasy. Viewers loved the brutality, the sex, and the feeling that none of the characters were safe (a reputation unearned for experienced fantasy readers IMO). In other words, the things that made GoT popular with broad audiences aren't hallmarks of fantasy overall, but within the genre they're fairly specific to GoT.
The problem here is that little of those non-fantasy specific things that you see in GoT exists in LotR or WoT aside from political intrigue in WoT, which doesn't happen until later books. They don't especially fit the ethos of either series. But I also think the people in charge are aware of this, so they try to identify elements where they can bring it closer, like with introducing Tar Valon politics so early in the WoT series. All that serves to do is muddy the waters and make the product more unfocused than it could be.