The elc files being included in the tarball is just a simple error. What I'm guessing has occurred is that the release version has been checked out of the repository, a make config and make emacspeak has been done to make sure it builds, then a make clean to remove the elc files and what is left, tarred up to create the release tarball. As the make clean target has not included the g-client directory, these elc files have not been removed with the make clean and then have been included in the tarball by accident.
This is an easy error to make and quite hard to catch - especially by the person testing and creating the tarball. If Raman unpacked the tarballl and tried the build, it would almost certainly have worked because the elc files would likely be from the same emacs version as that being used to build emacs from the archive. The error would only show up when someone tried to build emacs with a version diferent from that which was used to create the bundled elc files and it is likely it would have to be a considerably different version.
My guess will be that Raman will fix the make clean target, check out the 42.0 tag and create a new tarball for the download site.