What they are doing is stepping up the challenge of insisting in e.g. using Java 1.4 in 2018 (Yes I do know a few such cases).
Companies who won't shift of a JDK know this, that's why they pay for the privilege. They pay Oracle, or they pay someone to support an OpenJDK like Red Hat.
It's new for Java.
We don't care, for the purposes of the discussion, if it has been how things are since forever at SomeOtherProductOrLanguage.
We're not taking about the relative novelty of this release model (or its merits), but about how things are different now for Java releases.
Previously that was years on end.
People have already had years of support for Java 8 including support updates. By 2019 they will have had five years of it. Nothing's changed.
What's changed is that this wont be the case anymore for 9, 10, 11, and so on.
Plus, after 9, each new release will be out in 3-6 months (can't remember which) instead of years. And support for the previous n-1 release will end in the same day.
Plus, despite their frequency they'll have major language changes (whereas usually Java did much smaller scale changes + full backwards compatibility).
Well, that's a NEW development. And a major one at that.
Companies used to be able to rely on the same version of Java for years AND get security etc updates, without paying Oracle (and before that, SUN).
They might still do that, with OpenJDK, but not with Oracle releases anymore.