Soundwave on 28 March 2015
The smoking gun is the lack of a trailer or anything at E3 2015. C'mon ... there's absolutely no reason not to have a small trailer at least, even one that revolves around the story for a game that's been in development for almost 4 years and that they've already shown with two previous trailers/gameplay demos.
The reason they can't show it is because it's being tailored to the NX platform (whatever that is) and they can't very well show a game before the unveil the system itself.
They will unveil NX IMO sometime in early 2016 (allowing New 3DS and Wii U to have this holiday season) and announce that they've "magically discovered new wonderful gameplay elements" on the NX platform.
