This is an interesting point, and something that seems to be reflected in data here too. There is a good chunk of the data inbound on my personal ones that is EU sourced. Other people in #ntp are seeing a large increase from the US.
So another data point re US increase. One of my boxes in the US pool is at Linode, I don't run any other graphing on it however Linode provide some of their own graphs. Inbound IPv4 traffic for last month. https://www.dropbox.com/s/bhrutx8if1zr39l/Screenshot%202016-12-16%2016.07.22... CPU for the last month. https://www.dropbox.com/s/93zjxzn6dxl86qz/Screenshot%202016-12-16%2016.07.10... The traffic graphs for IPv6 show no jump like the IPv4 graph, it's doing 4x as much traffic as compared with a few days back, previously the traffic pattern has been fairly stable. Cheers, Joseph