Both when the classloader is null (a system class) and when there is no class or package-specific setting, the same default setting
from VMClassLoader.defaultAssertionStatus() is used.
There should instead a separate method for system classes as you mention: VMClassLoader.getSystemAssertionStatus()
(I don't think it needs to be called default because it can't be overridden by the class/package settings).
As we're just after a release (0.99), this would be an ideal time to add that method.