In an interview with BS by Dragonmount it explains a tiny bit more.


"So, I didn't send in a request--or even a question--about the future of The Wheel of Time. I was dumbfounded and honored when--a month or so after the death--Harriet called me on the phone to inquire if I was interested. I got the impression that she was calling several authors (I don't know how many) and making sure that they were willing before she invested the time in reading their work.

About a month later (this would be around mid November) she called me again and said that she had been touched by the writing of MISTBORN, and had decided she wanted me for the project immediately. However, she'd made certain to take time and think about the decision before offering it to me officially. At that time, she made the offer--and I accepted. (With great excitement.)"


So partly, yes, it was because of his words about RJ that he was chosen. After reading his books however, I love Sanderson's work, so it doesn't bother me too much.