I think the way Westbrook and Harden have taken their game up a couple of notches is mostly a coincidence, well that combined with teams generally playing a bit faster. Westbrook is basically on a rampage since Durant left and doing everything himself, while Harden's career arc probably would have had him playing something like this last season if it weren't for his attitude and D'Antoni giving him a license this season.
LeBron has basically been putting up the same numbers all season, the amount of near triple-doubles he gets is huge. He's averaging 26-8-8 for the year. It's only when he actually gets to the triple-double mark that people take more notice even though he does it pretty much every game.