I'm referring to the land specifically, since many states (especially out west) have a lot of land that is not part of any municipality. Unincorporated villages and towns exist in PA, but they are just geographic locations that are governed by whatever municipality they are in. I grew up in such a village that is spread across two townships (although there are no exact boundaries of the village).

As for Centralia, when it is unincorporated the land itself will become part of the surrounding township most likely.