In my experience, my last phone was a Note 2, and my brother had an S3. The Note 2 launched with features like MultiWindow, and it came to the S3 with a December update. My guess is that everything the Note 7 has that does not need an S Pen will make it to the S7 siblings in a future update. I believe the argument for the Note 4 and S6 comes with the fact that they are separate generations of phones. The S6 and Note 5 are the 2015 generation, and the Note 4 and S5 are 2014, so naturally they don't want to give too much to the past generation to boost sales of the newer ones. In this year's case, the S7 and S7E are likely needed to do even better considering the problems with the Note 7, to help them recuperate.