It's hard to tell, since the team is relying on the emergence of one or two contributors out of a potential pool of about 5 or 6 guys. Anything can happen in a situation like that, but my gut instinct is to expect a pitching staff nearly equal to, but not quite equal to, last season's staff.
Hitting will be the same I'm afraid.
As for this, I have no idea why anyone would think this. The team only lost 2 guys who had just awful, terrible years. The top 5 or 6 hitters are all coming back, and big things are expected from Bregman, McMullen, Laird, Barash, etc.
There's no way this team doesn't see a significant improvement in run production.
Yes, there are still lingering issues with the way the offense is coached, but that's a subject for another thread.