Since the code and doc agree, and since the proposal is to add a call parameter, this would be an enhancement for next release only, not a bug fix.

The proposal seems reasonable.  I might use it for IDLE.

IDLE uses .read within this subclass method.

    def Load(self):
        "Load the configuration file from disk."
        if self.file:  # '' for at least some tests
            self.read(self.file) 

The default config files in idlelib should be present.  (I should see what happens if not.  Does every 'get' pass a seeming redundant and possibly inconsistent backup default?)  I might use the new parameter here.  

User override config files and even the config directory are optional, so the current behavior is fine.