A trademark has been registered by Nintendo for The Legend of Zelda: Phantom Hourglass in Australia.
It's possible that it may be related to the 35th anniversary of the series. It's rumored that a remaster pack will be released for the Nintendo Switch, just like what happened with Super Mario 3D All-Stars for the 35th anniversary of the Super Mario series.
The Legend of Zelda: Phantom Hourglass, the fourteenth installment in the Zelda series, is an action-adventure game developed and published by Nintendo. It was released for the Nintendo DS in 2007. The game is a direct sequel to The Wind Waker, released for the Nintendo GameCube in 2002.