It would not impede the Nouvelle Vague itself: it gained traction the year before, with the 400 Blows, which was a heavy public success, so it would not slow down things. Godard was an acclaimed maker of short films at the time, and a frequent collaborator of Truffaut in the Cahiers du Cinéma, so he would have his debut later, maybe with Vivre sa Vie (in 1962), starring his muse Anna Karina and taking some of his gimmicks (breaking the fourth wall, ironic distance, stress upon dialog, etc.)
Jean Seberg continues her French career in another Nouvelle Vague movie, helped by the appeal of the depressed heroine of Bonjour Tristesse. The butterflies lie heavy on Jean-Paul Belmondo, who was a regular sidekick in classic French movies, disliked by the directors, before Godard noticed him.