"Heads up! Traffic Views Column Going Away" and "As part of the migration to a new stats system, we will be discontinuing support for the traffic views column in this report toward the end of July. We apologize for any inconvenience this may cause."
Note that the discontinuance only applies to part of the referrals page ( https://hubpages.com/my/earnings/trackers ), not the main hub stats page. I thought I'd better emphasize that so as to not start a riot.
The big news is the "migration to a new stats system" that is in the offing. Should be interesting.