You may want to clarify in the docs those steps will stop chaos monkey. As I read it, I understood it as it will keep me on a specific version of coreos not stop the chaos monkey. Am I misunderstanding?
The "random" reboots are the update process completing. If there is no update available, your machine will not reboot. Following those instructions will still enable the update to download, but not to be applied until you choose.
Our release cadence through the alpha has been about once a week, so 1 "random" reboot a week.