GR does not imply causality nor does it enforce it. In fact GR works in a non-causal universe without a problem.

2 very sensitive measurements conducted within the past year seem to suggest (if GR is true), that we are in a universe that lacks causality. 2/3 LIGO detections imply one of the merging pair of black holes should be a naked singularity.

GR allows naked singularities. It models them fine. GR just stops being globally deterministic.

If you look up the history of GR some mathematicians in 50's made some really weird proposals for non-causal universes that would appear locally causal. But there isn't a way to test this. So it is more pure mathematics or philosophy then physics.