I think that the Wonderful 101's release date pretty much confirms that GTA5 won't be seen on WiiU, or at least not at the same time.

[Kresnik]

Killzone Mercenary's release date got moved back forward a week because it clashed with GTA 5.

Using OP's logic, this is a sign we may be getting GTA 5 on Vita?

Excellent news!