I read the HuffPost article this morning and didn't find anything in it very compelling. The author begins "Despite valiant efforts made by parents, toy creators and even kids themselves to convince brands to produce gender-neutral toys, the divide between "boy" and "girl" products remains vast"--yet that really has nothing to do with the article. MLP, for better or worse, has always been a hyper-feminine product and marketed as such. So the "disturbing evolution" of MLP is not that the toy has become more gendered. Of course what the article really argues is that MLP has become more sexualized, which was a complaint lodged years ago against G3s.
I for one do think MLP was at its best in its early days when the ponies had more equine habits (after all, the toy was inspired by little girls' love of horses), but as many have said here, times do change, and while I'm no fan of the dolls, it will be interesting to see if little girls like them! I don't see anything about these dolls that is more "sexy" than Barbie or Bratz--honestly they seem less so.