Hint is the word, far more work needs to be done to come to any conclusions. It's also a little problematic because no mechanism by which an earthquake could be predicted has ever been established. The big famous one that was predicted in China in retrospect was an earthquake "that wanted to be predicted." IE yes, it gave all sorts of clear signs in the days before that something was brewing. No other quake has ever signaled such since. And then there's the fact that earthquakes themselves are still very poorly understood. Interesting preliminary study, but that's all it is.