Other stages also include behavior changes. Some changes are obviously age related. Others are more obscure. The stage of intense curiosity, hyperactivity and frantic chewing and digging occurs at the height of adolescence. This is also about the time that we recommend spaying or neutering.
People often expect an overnight cure for what they consider behavioral problems.
Sometimes the surgery itself is blamed for behavior that has nothing to do with the surgery but commences at the same time. She didn't chew and dig before the surgery, but she does now. A possibly reason is that she was spayed before she reached adolescence. I tell people not to expect dramatic or abrupt changes and that it can take as long as eight months for a recalcitrant rabbit to calm down. I'm implying that it takes that long for the hormone level to drop in some rabbits, but that also allows some time for maturity.