Ideas and creativity are not the problem here, there's plenty in the FF world and outside to flesh out a new healer job. Just like dancer could have been one if steps had a mudra like effect that would trigger heals etc.

I would not mind no new healer if SCH WHM and AST got a major revamp that would change them so much that they don't feel so identical.
But that's what I expected from ShB, and that's not what we got.