Due for surgery and my surgeon recommends a sports bra over a compression bra. As I've been reading up, is this wrong?

Each surgeon will have her/his own protocol for post op care. I encourage you to follow your surgeon's advice. You may wish to purchase the sports bra prior to surgery and have your surgeon approve it so you can feel comfortable that you will be properly supported after surgery.

Compression garments are specialized post-surgical clothing that aid in the recovery process. They’re made of elastic or cloth materials and facilitate a tight fit, applying constant and uniform pressure over the treatment areas. The garments must be sized according to the contours of your body to ensure a proper fit—poorly fitting compression garments might be useless or even cause discomfort. Research supporting the efficiency of post-surgical compression garments after breast or abdominal surgery is limited. However, some studies have shown that patients wearing compression garments like bras, girdles, and binders, after breast and abdominal surgeries demonstrate less scarring, swelling, and pain than patients who avoid them. Some studies have shown that compression garments have positive psychological benefits, reducing the patient’s anxiety and increasing mobility.