JDK-8034057 java 9 only?

[Robert Muir]

We've had reports from customers that are caused by
https://bugs.openjdk.java.net/browse/JDK-8034057

Apparently its not that uncommon of a configuration to SUBST windows
drive letters (like a locally mapped drive)?

Just curious if there is any reason fixes are held back to java 9?
Otherwise we are forced to hang on to some pretty ugly workarounds for
some time, as it tends to break applications completely.

Thanks,
Robert