IOTL, the gravitational center of Dutch Protestant discontent with Habsburg rule was actually located not in Amsterdam, which remained mostly loyal to the Spanish until it was captured by military means, but in Flanders, particularly the key port city of Antwerp. As the Eighty Years' War progressed, the Protestant population of the Netherlands gradually migrated to the north as Spanish armies massacred Protestant resistance in Flanders.
So, how can we flip the religious situation around and make it so that the OTL Southern Netherlands or Belgium are the Protestant stronghold, while the Northern Netherlands (mainly Holland, Utrecht, and Frisia, the regions around the Zuidersee) remain mostly Catholic or at least loyal to the Catholic aristocracy?
What would be the impact of a closer Protestant Dutch Republic (or kingdom, depending on the PoD) on the French Wars of Religion?