That's the thing: the CAD files, etching films, or whatever for this hardware must still be on file. R&D costs would be nil. Tooling & legal copyright costs would be all that is required.
Heck! I know it's not cutting edge technology, but I could be far more productive with a circa 1999 designed 68060 board in my Amiga than I could with a modern (vapourware) PPC or Coldfire board that runs faster but has no software for it.