During any eye surgery your eyes are exposed to intense trauma. This can cause anything from irritation to ruptures within the iris. This is usually the most likely cause of a deformed pupil. While it's not exactly un-common it is 'normal' in many post-op Optometry patients.
It is not uncommon to have an odd shaped pupil after cataract surgery. It is not a visual abnormality. I wouldn't say it is "normal" but it is certainly not uncommon.
I don't think it is that abnormal. I am pretty sure I have heard of that before. If you are really concerned about it you can always ask your doctor about it.
Ophthalmologists try to achieve a round pupil after cataract surgery with lens implantation. The odd shape of your pupil may affect your vision. The odd shape is due to iris sphincter rupture.