Then maybe porting it to the Wii U became more of a challenge than he thought? Or he did port it but wanted to actually optimize it for the hardware, with Nintendo on board. Or he was just lying; there's that too.

I really doubt this game will escape the 2015 window regardless. 

Not even close, it is among the list of the most anticipated but is not even in the top five according to gameinformer readers at least:

http://mynintendonews.com/2015/03/29/game-informer-readers-reveal-their-most-anticipated-wii-u-games-for-2015/

I hope is not delayed, the console could use some game variety and Devil's third may not be a masterpiece but it should be good enough to fill a void in the line-up, they had been polishing for almost a year since last E3, and that could lead to a lot of improvements taking into account Nintendo inputs and support.

anticipated? sure

The game is coming out in 2016 in Japan anyway, so I wouldn't be surprised.

There goes wii u 3rd party support..no wonder system sales are through the roof

We have not even reached E3 and we have more delays. I don't know is this Delaytendo's job or not. I can't blame them this time.

Really hope not. May not be GOTY but 2015 is looking pretty weak for Wii U if this game is delayed as well. I guess if it needs to polish, though.

Sounds like a parody of the Zelda delay, IMO.

No Xenoblade? No Splatoon? No StarFox???

Nah. To be honest, I'd never heard of Xenoblade until last year with Shulk in Smash Bros. The original game kind of flew under the radar here.

Splatoon and that look nice, but not for me. I'm looking forward to something different.