I'm not so certain that Canon will introduce new sensor tech just for an 1.6 ...
You are basically right.
Still, the most practical thing to do when introducing new tech is to put it in smaller sensors first .
In fact, that's what Canon is doing already with the S100/S110/G15 sensor - which is made on new tech.
Eventually, this new tech will make it into DSLR sensors as well.
At that time, it would make the most sense if it's used for 1.6x sensors first.
Of course this is not guaranteed and Canon might have other plans.
To me, though, a 7DII with the same sensor as the 7D is kind of pointless.