Well,
akshually... I was curious about this and did some digging. 🤣😂
Yves' portrait was definitely photographed by
Andre Rau. According to this article about those ads, Karl's ad is (unsurprisingly) credited to Karl, Yves' to Andre Rau, there's also a Linda ad credited to Demarchelier, too. It doesn't sound like the ad campaign commissioned photographers at all (because they couldn't afford it lol), so they licensed photographs and used existing portraits of the designers.
Elles ont marqué l'histoire de la mode par leur audace, leur impertinence et leur originalité. «Le Figaro» raconte les dessous des campagnes de publicité inoubliables des cinquante dernières années. Cette semaine, retour aux années 1990 avec Kookaï, le gratin des top-modèles et la crème...
www.lefigaro.fr
Sonia's photo was shot by Dominique Issermann (who shot tons of ads for Sonia Rykiel), and it (at least) appeared in the February 1982 issue of Vogue:
Vogue Archive via justaguy
ANYWAY... I can't believe I looked into this.