Not entirely sure what millésime means (my dictionary gives "vintage" but here goes:
"Vintage Creed (perfume) is created exclusively with the noblest of essences and the rarest infusions. It is conceived, realized and filtered by hand in the purest tradition of the House of Cered, founded in 1760 by James Creed. "
The language of courtiers was indeed French in the day, but one wonders why they haven't bothered to translate it for the French-impaired amongst their clientele. No, I don't think it's a marketing gimmick, or at least not a very good one.