When you start importing from sun.misc.* you've made the conscious (or ignorant) decision to write non-portable code which may well break due to any JVM release. It sucks that these people are going to have to update their code (or that end users won't be able to upgrade to Java 9 without adding special command-line flags), but it's not due to fickle Oracle developers, it's due to technical debt that's finally catching up to them.
What Oracle is close to "hey all you performance sensitive folks, we aren't going to support unsafe anymore, can you tell us what you are using it for and how we can migrate to that explicitly?"
It just so happens that one of the leading proposals is "leave in java 9 but make it explicit to turn on". This is probably the right way to do this (in my opinion) but it does have the downside of making neither camp happy (it leaves unsafe so the purists are mad, and it causes headaches for people using unsafe).
- deprecate in Java 9
- "make it explicit to turn on" in 10, offer alternative official APIs as fallback
- remove entirely when most people have switched