Nothing about what the author wrote actually indicates he believes what you're saying he believes. And I know him, so I can safely say you're completely misconstruing his intent. In fact, what you've written above is both irrelevant and incorrect. Knowing the possible outcomes is not contradictory to tension. When Dirty Harry points his revolver at the punk's head and pulls his trigger he either has a bullet or he doesn't. And assuming he's telling the truth, no one there knows if he does or doesn't. It's a binary event with two very well defined outcomes, but there is still a palpable tension. So you don't need "anything can happen" levels uncertainty to create tension.
That's because tension isn't just established by uncertainty; it also requires a sense of stakes. Of course you can set the stakes either in mechanical or narrative terms as you prefer, based on your play-style. Regardless, it's vital that the players believe that there are interesting consequences to their actions; Otherwise, you have no tension. What's wrong with Approach 1 isn't that the different outcomes are known, it's that the stakes aren't relevant and interesting to the events and characters at hand.
But again, this is all besides the point so let's not waste further words on it.
What I have written above is my experience and about my preference, so in a thread about "Do you like fail forward? and why or why not?" it is relevant.
This is a thread about what you like about fail forward correct? and there is more than one way to run fail forward, correct?
It wasn't until reading what You linked to that it became really clear what it is that I find dissatisfying about some applications of fail forward other than the simple disconnect that some of us feel.
The knowing of the possible outcomes is a tension killer "for me". It isn't a tension killer "for you". Again neither right or wrong, just different.
I think "for me" it is the difference between feeling like I am in a script writing room deciding that Indi is going over the cliff and "how are we going to save him" and feeling like you are Indi going over that cliff, and not knowing how this is going to end.
So again "for me" as "a player" I like fail forward when used as the DM decides the outcomes before the dice are rolled, but I don't know them until after the dice are rolled (And I only know the one that takes affect).
In each of his examples you could have removed the point where the DM explains the 2 possible outcomes, still used fail forward with the same results and it would "to me" have felt like it was a more in character experience. It would also have the advantage for me of hiding some of the more blatant disconnects (If you fail the lock pick roll it will start raining).
However I should have separated it from my reply to you. But as it was connected to the piece you linked to so I didn't, Sorry.
Clearly I misunderstood the end of the artical when he was saying "In each example, there's a bad way to handle failure that is quick, simple, obvious... and wrong:" I misinterpreted that if you don't use the suggest approach you are "Wrong".