Is the fact that The Way of Kings and rest of the books in the series are going to focus each one on a different character connected in any way to the fact that both The Gathering Storm and Towers of Midnight focused each one on a pair of characters?
No, not really. Most of my plans for the Stormlight Archive go back years and years to before I was working on the Wheel of Time. I would say that the The Gathering Storm / Towers of Midnight character split happened because of the book split, less than any real planning on my part. I had the character arcs and decided which ones would fit well together if I was only going to be releasing one batch of them at a time.
So the answer is no, but with the caveat that with the way my mind works, it may have been working in the same way in both cases.
If you are viewing this on github.io, you can see that this site is open source. Please do not try to improve this page. It is auto-generated by a python script. If you have suggestions for improvements, please start a discussion on the github repo or the Discord.