I checked the oldest comments and I don’t know if there was an original story? All the comments that discussed the possibility of twins as a theory also mentioned they saw the raws. And the raws have been ahead of the translations. Even the reveal chapter of the twin switching, was uploaded on July 31 in the raws
Well, the theory was already there because of the cover and I think it was quite obvious when Danwoo begins to notice the difference in attitude at the restaurant. There's also a chapter where someone looks at him from a hidden distance and we notice that he's blond, so the little clues were already there.

How the heck did people already know about a twin brother? They'd been saying this for a while, and I'm pretty sure this was before the original comic confirmed it. This was unnecessary, and I'm worried we're gonna go the "the whole time, you were with both of us" and the MC ends up with both of them. Because...ew? The twin brother seemed psychopathic anyway if he's pulling this.