Contrary to the name, Many Worlds is a complete theory. Bell's Theorem does not predict non-locality, rather it says that any local realist theory must satisfy

Contrary to the name, Many Worlds is a complete theory. Bell's Theorem does not predict non-locality, rather it says that any local realist theory must satisfy a certain inequality which is violated in practice. An assumption of Bell's Theorem which is so deep of an assumption that people don't even know they're making it is is that there's only one outcome to any measurement.