He means Windows can set a timer to wake up after a while to run scheduled tasks. You might not have noticed those wake timers because they are few and it usually works as expected with windows hibernating back after a few minutes.

The difficulty of disabling wake timers has been exaggerated, though. It's in the advanced power settings, there's no need for the big scary registry.

https://www.tenforums.com/tutorials/63070-enable-disable-wak...