Maybe they should have put the line

The browser does its best to manage disk space, but it may delete the Cache storage for an origin.

in a warning box.

You know, you could just improve this. All you need to go is find the github link for the article at the bottom of the page, find the edit button, and github will guide you through the rest of the process.

(I've done so myself a few times)

If you prefer you can also clone and make a pull request using standard git tools.