I would be utterly astonished if Apple didn't release the iPhone 7 and a new version of iOS in the fall. Their shareholders might be none too happy also. Given the veritable avalanche of information, precedent and user/investor expectations that points to this, have you seen anything concrete that would make us think otherwise?
Also, the release of the SE does nothing whatsoever to mitigate the case for bringing out a major iPhone upgrade at the usual time of year. The fact that the original iPhone was released in June even less so. Honestly, why should shareholders, who care deeply about how upgrade cycles drive sales, be willing to put back the new iPhone release another year for such reasons?
Yes, the SE is not a real factor. It could be only a one-time release or they keep it as third size and the next one will be released among the other two sizes in fall or only every two years in spring. Who knows...
It's just a feeling that something might change compared to the years before because there are much more rumors for the 2017 iPhone with real hardware and design changes and that 2017 is the tenth anniversary year of the iPhone.
They could also delay it just a few month (maybe just until January) or have very much kept very secret and the big changes are already finished for the standard fall release.
The only rumors I heard about a new iPhone this fall were: the headphone jack will be removed, later that it won't be removed. And something about a double camera lens only in the Plus or maybe an additional Pro version and later a larger+thinner(non-protruding) camera lens for the other sizes or just all of them.
Then there is of course like every year a slightly better battery, faster flash storage (maybe up to 256 GB) and a faster next generation CPU/GPU (A10) and the screen resolution might be higher.
More RAM seems very unlikely.
Thinner than it already is doesn't make any sense because the 4.7-inch is already too thin to hold it without a case.
The other changes are not very much. Who needs just a faster 6S and a better camera beside the people that don't already have one of last years phones? A higher resolution on a max. 5.5-inch display does also not make much sense. The RAM is finally enough since last year too.
BUT who knows... If iOS 10 has so many new and/or better features that it needs just more speed to work good, people of course will buy such a phone even without any major changes and the same design.