Auto success is already there. Characters with primary stat and trained skill automatically succeed in easy DC's. Those with also a racial, background, theme, and item bonus may auto succeed moderate checks.
And if I'm the DM, I don't need a rule that "allows" me to say some things are impossible. I'm capable of deciding whether intimidating a mad wraith into submission is possible or not, depending on the circumstances.
As far as I'm concerned, the article really just talks about things we already do. It's not new. Maybe he's saying, it should take less effort to achieve auto success under certain conditions. Maybe a good point, maybe not. I don't think it matters terribly much because we want to roll dice when it matters. Under stressful conditions, even the most rudimentary tasks can become a challenge. My young barbarian might be a great swimmer, champion of the youth olympics, but if I've never been dunked in ice cold water wearing hide armor, carrying a crossbow at my side, a greataxe on my back, only to feel creepy tentacles brushing my legs, I might panic a little. My performance will be influenced by the conditions. It's relevant for me to make an athletics check to swim in this case. And adventurers typically make skill checks under such conditions, since resolving the trivial is not quite so adventurous.
I think that small chance of failure is something players and DM's both enjoy, as it keeps things interesting. If I fail that swim check, and I'm pulled under water by the grasping tentacles, the druid might change to an otter and jump in after me to help, the warpriest might cast a light to scare away any creatures of the night, and the halfling thief might just use this opportunity to satisfy her curiosity about what I'm hiding in my backpack that I don't seem to want anyone to find out. It's often as interesting to fail, as it is to succeed in skill checks. And if neither outcome is interesting, then the skill check wasn't really necessary to begin with, and it can happen off camera, we don't care.