It's just a very ungenerous interpretation of a lot of factually correct things. Brandon Sanderson is, indeed, Mormon and while I've never heard him say as much explicitly, the way he talks a out his faith makes me believe that yes, he does tithe to the church.

As for the audio book stuff, when Sanderson was doing his massive kickstarter for his four secret projects, he said that the audio books would not initially be available on Audible/Amazon. He said this was because he believed Amazon had too much market power and that he was successful enough that he didn't need them and would thus withhold releasing his books on that platform. I don't recall him ever saying that they would never be released there. Partway through fulfillment of the kickstarter, he announced that Amazon had changed its compensation structure (for all authors, not just him) in the direction he wanted and tbuse he felt it was okay to release his books on Amazon's platform.

If you like heroic fantasy with unique magic systems, I recommend giving him a shot. I like to compare him to Marvel movies: not groundbreaking or innovative or the pinnacle of the art form, but competently made that hits all the emotional beats you want out of the story in a familiar and comforting way.