Characters that were revealed tied with a game released in Japan:
- Olimar (Pikmin 3)
- Toon Link (Zelda: Wind Waker HD)
- Zelda (Zelda: A Link Between Worlds)
- King Dedede (Kirby: Triple Deluxe)
Characters that were revealed on Nintendo Directs:
- Luigi (August 2013)
- Sonic (October 2013)
- Rosalina (December 2013)
Characters that were revealed on an anniversary of a game:
- Peach (Super Mario Bros.)
Characters that were not revealed on special occasions:
7 out of the 9 characters revealed after E3 2013 were revealed either on a Nintendo Direct or to commemorate a game released in Japan. Only one character was revealed on an anniversary and only one character wasn't revealed on a special occasion.
Therefore, it's more reasonable to expect characters to be revealed on Directs and tied to a game release in Japan.
All of this is to say that expecting the Ice Climbers today was unreasonable and foolhardy, while expecting Diddy Kong on February is more logical.