Have you been to a Mennonite community? Phones are no secret. They are not technophobes. They just do not adopt frivolous tech without considering how it would benefit society. Cars, for example, were determined to be mostly a tool for leaving home, which many old order communities thought would be damaging for their community.
Phones are not so. Phones let you contact a loved one in an emergency. Many people, depending on the community, will have one, and there's no shame about it. This article just focuses on a couple kids, but paints it like a widespread thing.
Headlines says Amish, so a phone should not be accepted. I stayed with a Mennonite before and she said Amish are no technology, then I think there was Old Order, which accepted technology up to like the Model T cars but nothing further, then Mennonites, which were essentially the same "group" (religion?) but the most advanced technologically, accepting all technology.