wait, I thought that skyward sword link... was the original??? you mean there was a link before him? i thought he was the first one!
It's more likely that SS Link is the reincarnation of the hero shown in the preview. There are many hints of this, such as when young SS Link looks up into the sky at the loftwings flying freely, he wonders why he feels this sadness and loneliness - a reference to how in the past, Link sent the island to the sky and looked up longingly, wanting to go with them but instead staying behind on the surface as he slowly dies. The young SS Link was probably feeling the remnants of his final memories from his past life, which were sad. Also, the crimson loftwing immediately establishes a bond with young SS Link - Zelda's father comments how it's strange how the two develop an immediate bond. This is most likely because the two have fought together in the past, and thus there's still that special bond between them that transgresses time.
By having SS Link be a reincarnation of the old Link, this will allow the manga to stay true to Nintendo stating that SS Link is the very first Link. And since the artists actually work closely with Aonuma (and need Nintendo's approval with the story), this is one part of the story they would have to stick to with SS Link being the original hero by making him a reincarnation of his previous self.
I didn't read the translation for the last panel of the manga preview when Hylia holds Link and cries, but it makes sense that in this story, since Hylia is reincarnated as Zelda, the old Link is most likely reincarnated as SS Link too. I wouldn't be surprised if somewhere in the manga, there's a reference to Link's reincarnation, which can allow the artists to play in more to the special relationship he and Zelda have, and reference their past lives to further strengthen that bond.