Yeah the feeding scenes were definitely intentional, although they've generally been geared toward the chestal (breastal?) region as opposed to general weight gain.
I've been debating giving one of the girls her own ending with a little WG, maybe Grace?
Meanwhile, I do plan to have the option for WG with a character in Endowed who will be introduced in the next update.
I, for one, wouldn't mind some weight gain aspects, especially if it adds some balance to the legs: often, female characters are depicted with skinny lower legs...and "topped" with fat thighs and big asses... Something I've never really been a big fan of... Also, I quite like a bit of a muffin top and/or chubby tummy. Heck, huge boobs on a chubby body would look more believable... (In any case, I definitely followed the game's storyline where all girls are to end up with massive chests, regardless of body size.)