PARIS — In one of the more unexpected runway trends of the moment, the middle-aged model is hot. (Also the edging toward middle-age-in-model-terms model.) It started with the return of the supermodels in Milan: Naomi Campbell, Kate Moss, Amber Valletta, Shalom Harlow. At times, they seemed to be making more news than the clothes. Now the trend has been building in Paris, moving past the celebrity billing into more insider names who strutted along the catwalk earlier in the millennium being sprinkled among the current Bambi-like crop: Carmen Kass, Caroline Trentini, Natasha Poly, Mariacarla Boscono — women whose bodies and faces look grown-up, and even sometimes lived-in. It’s a welcome, long overdue change, giving further substance to the idea of inclusivity, even if it is partly to do with the youth of the designers booking them, for whom such women represent formative history. After all, in a time when fame can last 15 seconds rather than Andy Warhol’s 15 minutes, “vintage” means last season and having been a big deal 15 (or even 10) years ago counts as being part of the legacy past.