"Will unbaptized children of baptized JW parents be destroyed at armaggedon?"
No, under sixteens are safe.My dad didn't take any chances though - he got me dunked at twelve in '73 just to be sure. Best thing is to start making arrangements at fourteen though and plan things in line with the assembly dates. There is a transitory arrangement for children of unbaptized parents. They will not be destroyed as long as they have not finished studying two publications (brochures included), but need to get baptized immediately afterwards even if under sixteen.
"Will baptized children of baptized Catholic parents be destroyed at armaggedon?"
Catholics do not take any chances, as they baptize their babies. Unfortunately, most Catholics are largely ignorant of the fact that even full immersion of a newly born will not provide any protection whatever.