The abdominal muscles have a great deal to do with your end result. However, it is not always a function of surgery.
First, the muscles have to be innervated normally. Some muscles might be flaccid due to de-nervation or stretching of the muscles. This does not sound like your situation.
Second, the muscles need to be in proper relationship to function optimally. If they are widely separated, their function is suboptimal. Here is where a surgical tightening can help.
Finally, there is the factor of muscle tone. Normal patients with normal musculature might have poor muscle tone (i.e. posture). This might be due to lack of exercise or due to habit.
A careful exam and testing can discern what factors are present in your situation. Almost all patients should try to achieve optimal toning and strength by exercising and also improved posture.