Basically everything he says in that is totally legit though
Changing difficulty to make the gameplay different on higher difficulties would be a big change - as you have to adapt your survival strategy when changing to a higher difficulty.
Moving difficulty selection out of the options and into world creation makes perfect sense - nothing to do with "waah waah player choice" or anything like that should even come into it. The difficulty is one of the components of the gameplay, and it effects the core mechanics of the world around the player, thus it should not be changeable in-game at all. It should be selected alongside the world type and gamemode because it is a part of those options.
Something else that bugs me, not related to it being easy, is the linearity of it. Oh but it's an open world game, you say? It sure is. But what is there to actually do? There is an objective end-point to your potential progression, a point where you have items which are just straight up better than anything else and there's no point in straying from those items. The point he raised about Smart Moving and armor weight is pretty much perfect. Something else I'd like to see is food not just being a case of "stockpile bread" - as you eat a food more often it should diminish the hunger restoration to force you to have different kinds of food, and refining food into better meals should make the restored hunger diminish slower to encourage people to do more than just eat it as it comes, and meals having other effects allowing people with access to different resources to have different bonuses based on that - a well-prepared fish meal bestowing faster swim speeds and longer breath time, something prepared from a food found underground increasing mining speed, stuff like that. If nothing else just having some variety so I can feel good about having a berry pie or sandwich now and again instead of living on porkchops and cake (which is admittedly pretty awesome)
I could keep typing for hours this stuff just flows