When his family and friends made inquiries to law enforcement as to his fate, they would be told that no records concerning this person existed. If they persisted, or went to the media, they would disappear also.
But he is still with us, and will become a media figure now. Depending on how articulate he is, and whether he is an effective anti-Trumper, he may even get a bit of a career out of his antics.
He doesn’t seem quite as stupid or venal as David Hogg, so that’s a minor plus.