What I was referring to was a difference in fat storage, not necessarily redistribution.
My theory: Fat was originally stored in stereotypically male fat storage areas. As I lost weight the amount of fat was reduced and I grew much more lean. After years of HRT, when I gain weight now, it's stored in stereotypically female fat storage areas, creating the curves I described.
It's not fat moving, it's fat being removed then new fat being stored differently.
As far as breast growth, I did lose most of the boob I gained from HRT. In losing weight my body became leaner, and the fat reduction was taken from all areas, including from the breasts. How much this will impact you will vary on a dozen different factors, but while I originally hoped I had enough to live without augmentation, such optimism was (unfortunately) largely misplaced. FWIW, when I speak of weight loss, I initially lost ~125 lbs, of which I've gained~50 lbs back. When dealing with that amount of loss and gain, some changes are inevitable.