The theory of what happens inside a black hole can have implications for what happens at the event horizon of a black hole and what happens outside of the event

The theory of what happens inside a black hole can have implications for what happens at the event horizon of a black hole and what happens outside of the event horizon, which could be testable. It does require the assumption that physics is consistent and that it isn't "Calvinball" with one set of rules outside and a complete different set of rules inside, but that seems reasonable.