The biggest argument I could see for stormlight healing bring the cause of the return of dalinar's memories of his wife is that stormlight heals a person to their spiritual ideal. This is why kaladin's slave brands didn't heal from stormlight. When dalinar heard his wife's name, he felt as if he should know it, and so he was healed. This isn't a perfect theory I admit, and I'm not sold on it completely, but at first glance this was my thought