With so many models currently pierced,or tattooe even those models with natural unblemished bodies into bondage, fetish, BDSM . I pose the question is Alternative now Mainstream completing a total role reversal ?
There are few if any mainstream models on any of these sites so to my mind it's all alternative and always has been.
Your use of the word unblemished I presume is intentional and with the intent of inciting some kind of reaction from those who choose to adorn their bodies with tattoos and piercings. It's not a word I would have used.
Trends are trends, I have no idea what mainstream or alternative as descriptions are supposed to mean? I suspect the terms have little or no meaning. Tanning, cosmetic surgery, better dental surgery, underwear or tailored clothing, whitening teeth. Hair dyes, heeled shoes...which combination or application of all these defines either state?
Look at all your mainstream content, I don't see an abundance or even barely any of these models in Vogue, Elle, Cosmopolitan etc. Nor do I see these kind of models adverting for M&S, Debenhams, Miss Selfridge.
I could go on, but I simply don't see models like this used in any kind of mainstream at all. In fact there are lots of other specific qualities they require.