If you read the article carefully, they call it a 'forecast', not a 'prediction'. Also, they explain the difference between a forecast and a prediction.

Forecasts are useful for telling us where big quakes are more likely to happen in the near future so we know where to spend money to prepare.

If you have two places, X and Y, and they both have the potential for a magnitude 8 earthquake, but X has a 90% chance of happening in 10 years and Y is only a 10% chance in 10 years, which location do you try to prepare first?

Brian