Yes they have; they first got the data on this back in February.
Now, I’m not saying we should then force 13 feet separation. There’s a drop off in the risk that makes that unnecessary.
Only that yes, we have confirmed the disease can travel that far.
Considering the infected cruise ship was known to be circulating the virus in the air vents, we already understood that further travel was possible. Just not how often or quite how far.