Except that the marriage of her daughter would be controlled by her husband. So say instead of a son Joseph Ferdinand she had a daughter Josepha with Max Emanuel or with a new husband, be he a Neuburg or Sobieski. Her husband would have custody of the girl and be able to control her marriage. I'm sure Leopold would want her married to his son Charles but in also sure Louis XIV would pull out all the stops to marry her to his grandson Philip, Duc d'Anjou. She would basically solidify either claim. So that gives her father enormous leverage.
Neuburg would likely go along and marry her to Charles, maybe he gets a little something like being made Governor of the Spanish Netherlands. Max Emanuel might actually go for France. Sobieski is a big question mark.
A daughter by a dead Max Emanuel would likely go in Austria with her mother and remain in custody of her maternal grandfather when her mother remarried (unless Antonia married Carlos II). If Antonia had married Neuburg (who is neither a ruler or heir apparent) they will likely stay in Austria and in any case he is Karl’s maternal uncle so marrying his daughter to his nephew would be the most logical thing to do for him also...
Sobieski will most likely use Antonia’s daughter for getting some big concessions from a Leopold in exchange of the custody of the girl.
Max is the only one who can be tempted to go for a French match (as Anjou is his nephew) but that would mean losing the job of Governor of Netherlands and make of Leopold an implacable enemy.
Much will depend also from where is when Antonia died: if little Margaret was in Austria (and is pretty likely) you can be sure who Leopold will not give back his granddaughter to her father.
