The Island Event that causes the name to be changed to a ? is not a glitch. The villager falls out of a coconut tree and gets amnesia, so he can't remember his name (thus the '?').

In vv1 I had several people have thier names change that were on the detail screen just after the other person.
There isn't a coconut tree in vv1. And it would happen after I would shut the game off and get back on. I am sure that is a glitch.
Your right about the coconut falling and giving a villager amnesia. That happened in an Island event.
The Isaland events in this game I really look forward to. They are really different.