Any projects that does not have official headcount gets that tag line. Even some projects that are funded internally, may get that moniker externally as there's no guarantee it will be maintained.
Most of the time these are projects that individual engineers go through the pain of open sourcing.
I'm talking open source here. When it's funded, there will be people to help fix issues and put out new releases. This includes things like Go, Flutter/dart, k8s, and others.
Yes, any of those could be defunded at any moment if it was no longer advantageous for Google to support it, but for now, they are getting support and new releases.
They have a few products you pay for and are thus supported (for consumers YouTube Premium, Google One which is Drive storage+support, for organisations Google Cloud, Google Workspace), but for everything else, yeah. Unless you pay for One, you get no support from them on the random free stuff like Keep or Maps - you get what you pay for (in reality much more than that, something like Maps is a massive effort everyone can use for free).
It's not really that sort of project. In principle, this is all stuff you should already be doing. But, statistically speaking, $YOU aren't. Even if they disappear today, you're probably still better off picking this up and starting with it as-is than you are with your current server.
While I'm sure this is the sort of project that could benefit from ongoing improvements, it is also not going to decay away into utter uselessness if nobody commits to it in a week or two.
I understand the need for projects to be maintained, but I think some people have been badly burned by the Javascript world, or possibly some other language environments, and don't realize that those environments aren't the norm, but one of the extrema. Go is quite possibly on the other extrema. It does not generally decay. Again, I'm not saying that means it's totes cool to pick up a security-based project with a last commit from seven years ago and just assume it's still cutting edge, but this sort of Go code doesn't require a dozen commits a month just to tread water.
As someone stuck in JavaScript hell, I think you have a great point. How nice it would be to not touch a project for a year, come back, and not have to rewrite it just to upgrade dependencies.
Should google put this on all their products? You know, just in case?