TimeZone and logging are the two core libraries components that maintain a global state across a running JVM and was not designed for applets isolation. To support applets isolation, the implementation has changed to maintain per-AppContext content that introduced the dependency from core-libs to sun.awt.AppContext class through sun.misc.JavaAWTAccess.
Logging uses AWT and timezone whereas AWT uses logging that will call timezone for the default log message format. This circular dependency is error-prone and hard to diagnose (JDK-8014718).
JDK-8001029 will remove the dependency on AppContext. This bug is to break the logging / awt circular dependency on the lazy initialization of sun.awt.AppContext.