Aww, they pulled the image of the not-blue dragon. I mean, if nothing else someone should have noticed the lack of a big-ass horn and desert environment, but now what will people have to talk about?
Because seriously, there is barely anything of interest in the rest of the article. All he really needed to say was, "We realize that many Dungeon Masters just level the characters up when it makes sense, and that is a method that we are supporting," and wrap it up. I cannot imagine the "official rules" demanding much more text than that.
It would be nice to see something, anything, more substantial. Or substantial at all. Instead we get boring, pointless, and mostly harmless filler. The only point of contention I have is where he says that tracking experience "makes a lot of sense in open-ended games", and kind-of infers that open-ended games are less story-focused. I...guess they can be, but my last few campaigns have been open-ended, featured plenty of story, and I still leveled the characters up whenever I felt that they had done enough to warrant it.
That aside I think this is actually mostly good news, because I also think that how Dungeons & Dragons uses XP, like extra lives in old school console games, no longer serves a meaningful purpose. I say mostly because it is incredibly easy to just houserule milestone-leveling (or whatever you want to call it) into your home game. The real benefit is its "official" recognition for published adventures, which I firmly believe would have been universally improved if they were written using XP for encounter budgeting and nothing more.
I remember trying to create my own adventure paths, cramming in enough encounters and quests to "officially" level up the party: for me it was at best frustrating, at worst a fucking nightmare. For my players it was often a borefest going through yet-another-encounter-with-crab-people, or whatever the thematic monster was at the time.
Once I started just leveling the characters up when they completed meaningful objectives, like defeating a big-bad or recovering a legendary artifact, I felt like a massive weight had been lifted from my shoulders. I was free to structure the adventure how I wanted. I could include the encounters that I felt warranted inclusion in regards to how relevant and engaging they were, and I also had complete control over the pacing. It worked out a lot better instead of trying to shoehorn in enough, say, kobolds to make sure that they got to level 3 in time to grind orcs.