The 60,000 year figure is pretty dubious. Also saying they've avoided contact or still live in the stone age probably isn't true. Obviously they are ignorant of the workings of helicopters and modern fishing vessels, but they likely understand what the purpose of them is. So they've been contacted, they just prefer not to interact.

Given that they live on an island, I'll bet they make use of all sorts of materials that wash ashore. Even a torn plastic tarp is very useful compared to having to make one by hand from some plant material.

So culturally they are likely completely isolated, but likely very aware of the changes going on in the world outside their island.