Pete mentions riding the course to set out the splits. It prompts the question, could folks accept a full ten-year renewal on one of these (long, difficult or dangerous to measure, etc) courses as long as there is at least one full new measurement of the whole thing? That would mean that, in fact, the measurer's assumptions about the old segments has been confirmed.
In fact, what if you go to measure any expiring course that hasn't changed, and you measure it once and find that in fact, it hasn't essentially changed, do you have to measure it still another time? Assuming your measurement comes within 0.08% of your original, 10-year old measurement?