I will facetiously joke and say that WotC's true design goal is to merely reproduce the 2014E game, except making Beastmaster Rangers, 4 Elements Monks, the Weapons table and the Stealth rules cleaned up and made more explicit, plus removing the +10 bonus damage from the Great Weapon and Sharpshooter feats...
...just so players will finally
shut up about those stupid things. They've been whining about them for 8 years and they won't ever stop.
Anything past that? It's indeed just moving chairs around trying to clean up some language and make a few series of instructions clearer. Not totally necessary, but if you're going to re-produce the book anyway, might as well do it. But there's never been any intention of turning this new version into something 2014E is not. It's not 4E, it's not Level Up, it's merely a spit shine on 2014E. That's it. And if you don't like 2014E... there's absolutely no reason to bother following along. You're just just going to make yourself upset.