Will leaving the implant capsule (under muscle) interfere with mammograms?

If the capsule was thin, it will likely resorb and likely should not impact your mammograms to any significant extent.

With under the muscle implants, the capsules are behind the breast tissue and muscle, so they won't get in the way of mammograms or breast exams.  As long as they are not thick and calcified, they are expected to resolve on their own after implant removal.