Windows 7 allots a percentage of the hard drive for restore points. When the allotment is exceeded, the oldest restore points are removed by Windows 7.
In my personal experience with CCleaner through the years, I have to actively select the restore points to remove from the tools/system restore tab. Selecting this tab automatically scans for restore points. Then it goes into passive mode until the user initiates action. All other scans are in their own tabs and are not automatic. One has to initiate the scan and follow through. Restore points are not part of these scans.
I tend to keep the number of restore points under ten. After the monthly Microsoft updates, the number of restore points tends to balloon.