I didn't have a reduction but i had argumentation in 02 and in 06 i was able to breastfeed and in 2014 with no issues.
I haven't had a breast reduction but in 2010 I had lumps removed from my breast, (my scar goes around my nipple). I produced milk in my last pregnancy last year, so i know it hasnt caused a problem having an op. I'm pregnant now and plan on breastfeeding. Hope this helps.