Not sure what these white dots are after removal of nipple & having it sewn back on in 2019 (Photos)

I doubt your nipples were actually removed and sewn back on, but excess skin around was removed while your nipple-areola complex stayed on the breast. You did lose some pigment (white dots) on your nipple. You can have cosmetic, not artistic tattooing to replace the color lost.

It is unlikely that these color changes are related to your breast augmentation/lift surgery since they show up so late. They appear mostly around milk ducts and may be something to do with it? Do you have any similar color changes else around your body?

Those dots are loss of pigmentation which can occur. It might come back with time or you can get tattooed