Wasn't Triforce Hero mainly developed by Greezo? Never understood why people thought it would take away dev time from the next Zelda. It borrows many assets from LBW and the TFH Link sprite actually looks less detailed than LBW Link as well (probably to have 3 Links playable on one time though).
Console Zelda games take forever anyway because Nintendo likes to faff around with development by deciding on what graphical art direction they should use after perfecting the gameplay. Because of this, they are are always the in jeopardy of not being exclusive to their originally planned console if said console has poor sales. In contrast Mario, Pokemon, and Smash Brothers always end up on the console they were made for.