Personal Environment: Wakeup and Restart Personal

We have on-premise environment and so Personal environment is not being actively used. As a result time to time, I receive email to "wake up" the environment. 

This time after receiving the email, I acted to wake up my personal environment, but it followed by asking to "Restart Personal"

Is this a new thing? What restart does? 

It also comes with fine text..

All Personal Environments run on a shared cloud infrastructure. If your environment hits the allocated CPU or memory consumption thresholds, it will get suspended until you restart it.

To find out how to avoid being hit by these normal shared environment constraints, check out the paid tiers in our pricing and editions page.