You could be right. If you look at the chart for active folders you'll see a spike on 2/15, another on 2/5, and another on 1/26, which is every ten days. So maybe we have a bunch of machines that happen to be completing 10-day WUs at the same time? I have some machines that are doing the same thing--they just spiked a couple of days ago.
Every 10 days--that would be my processors, to name a couple. That comes to about 500 pts. Tinker core units take forever.