I doubt they'll do it because of story reasons except if you play with shadowheart as your avatar and they let you set her entire setup (speaking for myself I hope they lock classes for companion avatars because I find an immersive story more important than perfectly optimized group composition). Gameplaywise of the three currently in EA accessible domains light, life and trickery only the latter should even be available for a clearic of Shar. Another reason not to change that. I think storywise it fits perfectly well that shadowheart is a Shar cleric with trickery domain.
