You don't need to specify the myaudios-1.0 section, that's implicit in the search paths along with the unversioned ${BPN} and files/. SRC_URI="file://myaudios-1.0.tar.gz" will find it and also work with every previous Yocto release.
This must have worked previously because the search path logic was rather overcomplicated and unpredictable. It was recently cleaned up but obviously you were unknowingly relying on undocumented behaviour.
I have not tested this back on Danny, but it seems to be past the point where it couldn't find anything. I have no idea how it worked in the past. I remember having to toy with it a lot. I'm still not clear about all the paths in a recipe. So I just copy others and try things that eventually work.
