I just checked the code on the promoted branch and the bug I reported exist there. However, please note that my debugging was done on Linux and perhaps the GetSourceIniHierarchyFilenames function is called differently for other platforms.I guess other platforms may initialize the audio differently, IDK. I will check on that later today. What platform are you using? Do you see the audio initialize in the console output?
I do know that on Linux, the [Audio] section of the LinuxEngine.ini is never loaded due to the reasons I reported. However what your seeing could be a bug specific to the platform you using.