Zelda Informer: "Awhile back a good friend of ours, Branden Casper, presented a nice editorial analyzing the reveal of Zelda U at E3 2014 and suggested the game could be a prequel to Skyward Sword. His basis mostly stemmed from Link’s garb and the technology presented. Now that we’ve seen more of the game I’m not inherently sure the game is a prequel, but I am positive that it is related to Skyward Sword in some fashion.
There were things going on before Skyward Sword happened. This was referenced in the opening scenes of the game and since the hero’s clothes were supposedly based off Loftwing riders from the Skyloft Academy, Link not rocking his traditional garb could mean theoretically that this Link is before that garb became tradition. We have some new footage and I find it neither proves nor disproves Branden’s thoughts, but it does solidify that this game relates to Skyward Sword in some fashion."