A “cooldown” is exactly what it sounds like: a window of time between when a dependency is published and when it’s considered suitable for use.

My understanding of a cooldown, from video games, is a period of time after using an ability where you can't use it again. When you're firing a gun and it gets too hot, you have to wait while it cools down.

I was trying to apply this to the concept in the article and it wasn't quite making sense. I don't think "cooldown" is really used when taking a pie out of the oven, for example. I would call this more a trial period or verification window or something?