Actually it doesn't even say that - they claim to have the same "accuracy" at 3 days that older methods have at 2 days. What does that actually get you? Were the older models so much less accurate at 3 days (compared to 2) that it prevented evacuation of key areas? Looking at the paper, it doesn't really seem like this can be answered yet because there's not enough data over a long enough time.

Keep in mind, DeepMind has a very well documented history of releasing enormously hyped up PR pieces with grandiose claims that are never backed up in real world usage, or are simply lies.