Hmm. The policy was "a release published in the last 6 months", which sure, could theoretically be an old LTS branch. There certainly wasn't a culture of doing that though. I remember a huge scramble to move everything over to Java 11 (honestly a lot scarier than an OS upgrade in that context) which I'm pretty sure was based around 6 months after the first release of Java 11 rather than the EOL date for Java 8, but it's possible those were the same thing.

Well, I'll tell you how I know the policy I'm talking about is more popular than the one you're talking about: LTSes themselves, and vendors offering extended, enterprise support for old software in general and OSes in particular.

If enterprises would consistently and massively upgrade early (for example within 1 year of a new release), vendors wouldn't need to offer this super long support on such a widespread scale. There's a reason Windows Server is supported for so many years, or RHEL, or SLES, or Solaris, or whatever.

It's popular if you weight by dollar spend, sure. That doesn't mean it's popular if you're weighting by actual productivity.