Yeah, I've had pretty good results here digging and replanting as soon as bloom is done (or even before sometimes), so I figured why not mail them then too. It mostly boils down to when I've actually got the free time to do it ;0)
Also, although I could see where disturbing them in the middle of active growth could set them back for a little while, I've always thought that the sooner they get a chance to start settling in the better. And I've had some late season shipments that have taken almost a whole year to get going. It would worry me more not to have good roots before cold weather comes. We get lots of "frost heaving" here.