No one is passionless. There is certainly a spectrum of how excited people get about their passions, but everyone has some non-zero level of passion.
Granted, some people aren’t aware of a passion. They couldn’t articulate it to you. But it’s there somewhere.
The job of the facilitator is to ask questions that are more approachable than “what’s your passion?” Questions like “what do you love to do?” “What do people ask you for advice about?” and others.
Kids don’t need more exposure to new ideas before they “choose” a passion. The conception of “passion” as singular is dumb and the only way to even pretend to have a passion is to make an arbitrary choice anyways.
Might as well choose something soon and use it as a guide to gain exposure.