Every person has asymmetry. Your surgeon or implants will not change this!
No matter how similar you think each breast is, there are differences that will be magnified once you have implants. Subtle differences you may not have noticed before (because you didn’t spend a whole lot of time inspecting and critiquing your breasts), will be magnified by implants. Especially considering you will probably spend a lot more time examining your new assets.
One nipple will be higher than the other, one breast more full, one fold higher on the chest, and you may have one nipple that points more laterally than the other. Your breasts are sisters but are certainly not twins, and implants will make them twins! Whilst your surgeon will spend time evaluating your pre-operative anatomy and point out any differences they see, it is important to understand the limitations and effects of implants.