In OTL the Spanish Netherlands went to Austria after the War of the Spanish Succession, but is there a way to make them go to the Dutch Republic?
Originally the Dutch Revolt had the intention to gain independence for the entire Burgundian Netherlands and not just the Northern Netherlands.
After the treaty of Münster/Westphalia both sides started to drift further apart, with the Southern Netherlands staying Catholic and the Northern Netherlands being dominated by protestants.
IOTL the Dutch Republic, or at least a part of the political establishment, wasn't to keen on having to control that much Catholic subjects directly and preferred the OTL influence instead.
In other words an earlier pod IMHO would make this more likely, however it still isn't impossible either.