i just recently had the same theory... (yesterday) i posted it on facebook, so imma just copy pasta that puppy rite here. it should back up your theory while using some other games, and add a bit more detail as to how the story could be. HERE YA GO:
As you may know, Ocarina of Time was never truly concluded. Link returned to the past, and chose not to remove the master sword from the pedestal, knowing that doing so would open the sacred realm, allowing Ganondorf to obtain the power of the triforce (he got power). because link was not yet old enough to defeat him, he was forced to sleep for 7 years, giving Ganondorf the time he needed to gain power over Hyrule. After Ocarina of Time, link travels to Termina in search for Navi, who left soon after link returned to the past. In Termina, link is given the challenge of saving Clock Town from the falling moon. during this time, Ganondorf is free to do as he pleases in Hyrule, although this would likely consist of trying to get the triforce, considering he's as far as we've seen, useless without it. As is explained at the beginning of Wind Waker, the people waited for a hero to arrive, but he didn't show up in time to save them, and Hyrule had to be flooded. it is clear that at the end of Ocarina of Time, that the triforce is sealed within the sacred realm, yet we see in Wind Waker, which is commonly agreed upon to be a sequel to Ocarina of Time, and Majora's Mask, that the triforce is scattered across a flooded Hyrule. It is clear that there is some link (pun) missing in the story, my latest theory says that the next Zelda game will take place in this gap.
Many people believe the girl in the Next Zelda's concept art to either be the queen fairy from Wind Waker, or a humanoid form of the Master Sword. In this theory, i am leaning more towards this being a fairy, although a sword nonetheless. I believe the plot is likely more about link avoiding using the master sword, in order to keep Ganondorf away from the triforce. Considering Wind Waker has the triforce shards scattered across Hyrule, it is also likely the sacred realm is opened. also the master sword is still in it's pedestal in Wind Waker, so perhaps the sword was returned once Ganondorf is "defeated" (he is clearly back in Wind Waker, although not in complete power, so he apparently hasn't been free long). Ganondorf quite possibly kept his piece of the triforce, and it is clear Tetra gained her piece from being a descendant of Zelda. it is possible in the upcoming Zelda that link never passes on his portion of the triforce, due to reasons i haven't yet thought of. although perhaps he had to leave Hyrule again, hence why the Master Sword is returned.
ADDITIONAL THOUGHTS: (sorry, but no they wont be in caps lock)
In Majora's mask, Link has the ability to obtain the "Great Fairy Sword". This shows that the fairies are quite proficient in creating swords, and the great fairy sword in Majora's Mask sort of resembles the great fairy mask. considering the "fairy girl" in the concept art, perhaps she is indeed a fairy, but has the ability to transform into the sword as well, (this is from many theories other people have had, including myself). Since link has yet to find Navi, perhaps this is her... it is possible Ganondorf was able to gain entrance to the sacred realm, and get the triforce before Link is able to return. Perhaps within this process, Ganondorf breaks the master sword, similarly to how Vaati breaks the four sword in the Minish Cap, in order to gain entrance to the sacred realm, ignorant of the sword's power (Ganondorf wouldn't know of the master sword's powers, because Link never defeated him with it yet). perhaps, after finding Navi, She fuses with the Master Sword in some way, allowing the blade to be repaired through her sacrifice, although by doing this, shw is allowed to change to a more human form at points in the game, such as in the concept art i have previously mentioned so much.
although Navi was annoying with all of her useless information, she was a very loved character, and it would be crazy for the Zelda team to not bring her back in some form. Zelda games, although vaguely, and arguably, all have some way of being linked together. They also enjoy recycling ideas, such as the idea that Twilight Princess is a parallel story to a Link to the Past (Mirror = Mirror, Tark world = Twilight realm, Aganhim = Zant, etc). Knowing this, my only questions are, if this is the same link as OoT, why is he clearly right handed in this game, yet left handed in the old ones, unless it's just a quick solution for the right handed Wii remote, such as in TP.
