This only for Oracle JDK. Oracle provides support for old versions of JDKs. So enterprises who have not updated their old software targeting old versions of JDK need to buy this support.
Yeah Oracle has them in a bind as long as the cost to replace the java codebase is more expensive than what Oracle charges they will keep paying. Most of these are probably my guess old banking and accounting systems. I wonder if any US or other countries different departments pay for it as they could take years to move away from it. Oracle I feel is the company that behaves like a gangster as most of their tactics are similar.
This is just for Oracle's implementation of the JVM which has features and enterprise support capabilities that other implementations don't.
No company has or is ever forced to use it. And no one is going to replace their Java codebase because of this. They will simply swap for a different JVM like many of us did years ago.
Cost of that support contract is going up.