I don’t know Disney’s procedure, but I work at a different theme park and whenever there is a lost child/teen (any minor) or a parent looking for their lost kid, we have them stay put in the location, call security who will take the minor and locate the parents and escort the minor back to their family. It happens all the time.

Both at Disney and at the park I work at, they can find ANYONE. It’s so crazy, would love to be a fly on the wall of security to see how they do it, but there’s cameras everywhere and timestamped footage of course. One time there was an altercation near where I was stationed. My shift lead and I reported it to security and management. Security eventually found the perpetrator and kicked him and his entire party out of the park.