Depending on the strength of the Swedish victory at Nördlingen, this could delay direct French intervention during the Thirty Years War. It could even butterfly it depending on how great the victory is for the Swedes and on what happens after Nördlingen.
The Cardinal-Infante was leading his large army to the Spanish Netherlands. If the protestant armies win at Nordlingen, he doesn't get there. France may seize the opportunity and try to finish the Spanish Netherlands off.