We have too many guys fighting for taken spots. Mushfiq, Nasir, Shakib, and Riyad have 4-7 locked down. Naeem may or may not be able to hold his position, but he's not a terrible option either way. Gazi I think can bat well enough to be considered a prospective all rounder. He could easily be a guy who can average 20-25 in both formats.
I think Abul is being exposed for the ordinary bowler that he is and I don't think he can replicate his batting form either. Anamul will take one of the opener/one-down slots. Meaning we need a #3 batsman. Marshal, Mehrab, Ashraful, and maybe some others seem to be in contention for that.
Bangladesh is a stronger team with Shakib al Hasan.
Bangladesh is a stronger team without Shakib al Hasan.