In light of the above and The Church's teaching on predestination, it seems to me rather straighforward to conclude that all the predestinate will not only be baptized but die in a state of grace and in communion with The Church.
Except the Church doesn't teach that.
If the predestined will be infallibly saved (and they will be) and if the dogma of no salvation outside The Church is to have any meaning, it is necessary that they die in a state of grace and in communion with The Church in order to attain salvation. If baptism is truly necessary for salvation and it is the door by which one enters the Church, then they will be baptized as well.
Sure, God is not limited by the Sacraments, sure, God COULD save anyone he wants to by whatever means he wants to. But such is the realm of speculation and not that of actual Church teaching and it is wrong to presume that God will actually do differently than what he has positively revealed to us through his Church, that he will use other means than the ones we know he established for our salvation.