For vast amounts of people (probably well over majority, but who knows), if it doesn't show up in a Google search, it might as well have been deleted from the internet. Hell, try running a business that doesn't show up in a Google search result. You might as well not exist.

EDIT: Also, keep in mind that many sites now use Google as their search tool. So going to the domain and searching for an article in their website that you've seen in the past wouldn't even work.

I'll admit my first thought, based on the wording, was that the articles were posted on a google service such as google docs.

From the headline alone, my initial assumption was that it was about a google-hosted website and the content was actually deleted. Then I read the article…

Without further context than the title provided, it could mean that they deleted the articles from another Google property, not search results.

Not sure what that property would be. Blogger perhaps if that is still a thing?