Yep, I remember this, though not the details about the 6 sides. But yeah, it looks like Owen is now saying, that this was not the correct interpretation of the story. In the past, we were viewing a writer's rendition of a tale told by someone else, who knew someone who knew Owen or Doom, who presumably had told them what really happened.
It's a retcon that serves the story, that's what comic book writers do these days
"It's not whether you win or lose, it's whether I win or lose." - Peter David, on life
"If you can't say anything nice about someone, sit right here by me." - Alice Roosevelt Longworth, on manners
"You're much stronger than you think you are." - Superman, on humankind
All-New, All-Different Marvel Checklist
I really prefer the pre-Hickman take on the Cosmic Cube beings.
It was a good nod to Fantastic Four # 20 and why the Watcher was so concerned that Owen Reece exists. Most appearances with Owen wasn't taken serious enough, but Bendis' Dark Avengers really showed how you could use something as powerful as a Molecule Man, while still not using his full potential. Hickman greased it up a bit and we have this Silver Surfer MAX Herald of the Beyonders.