I saw that the Berlin flight went to Syracuse, so I decided to see where the HKG flight ended up. And to my surprise, it made it into EWR after all... just an hour late.

To the other poster's point, I'd rather be diverted domestically on these longhauls than be stuck at the point of origin with a cancellation. It means as a passenger you'd get to the airport sooner ...and for the airline, it means they can gradually get their operations back to normal sooner. Plus on the longhauls, a lot can happen during flight time with the weather...so it's not worth the gamble.