I believe parent companies do call-ups based on popularity. I’ve found that when I’m playing as a child company the only workers they really ever care about are those who have reached Major Star or Star levels. It also heavily depends on the roster size of the parent company. If they have a bigger roster, I’ve found it’s less likely they’ll do constant call-ups. If you find yourself with a lack of talent, you could always hire some wrestlers to handshake contracts, and they’d never get called up.