The risk of complete capsule removal in under the muscle implant positions is too high ion some cases and best to leave it if there is no ruptured implants. If you have old silicone gel implants that has ruptured, then should have the entire capsule removed safely.
The scar or capsule will remain. I don't perform partial capsulectomy in patients who are having explants. They either have all of the capsule removed or none. Usually if they have no capsule removed I can have them improve their volume with fat grafting.