Unfortunately this isn’t the case. Around 20–50% of women suffer from PMPS — post mastectomy pain syndrome. (Wide range because it’s so under-reported.) It’s theorized that it happens due to nerve damage during the mastectomy. There’s a whole FB group dedicated to this issue. Some women don’t have any reconstruction and still suffer. Some have tissue transplant and still suffer. So it’s much more widespread than acknowledged and very difficult to treat.