This is still on retrospective data. The machine learning graveyard is filled with models that worked well on retrospective data, but did not hold up in a live inference setting. Just ask Zillow. The real test is whether they can predict the weather 14 days out in 2025.
I am guessing they did not want to set up the data pipeline to run inference in a live setting. But that is what I would need to see to be a true believer.
Still a cool result and article though.