Wouldn't it be better to name it "elpa-build-system" as that's what it is in my opinion, since it does not retrieve the source directly from upstream but from ELPA/MELPA/... "repositories" instead.
I imagine there may appear another build system for simple emacs packages (that don't provide Makefile, etc.) that will compile elisp files, generate autoloads and so on. I think it will be a system that should be called "emacs-build-system". WDYT? -- Alex