This difference in purpose Desktop -vs- Workstation cannot be lost because the end product cannot just be another version of Fedora Desktop with more up to date Gnome Shell components, it should be a TRUE workstation-class product. There's a huge risk that the Desktop use case will creep into the Workstation product. To ensure further separation there should be two different parallel tracks based on which desktop environment is in use:
Fedora Desktop = Core + Gnome Shell (Gnome 3)
Purpose: "Deliver a cutting-edge mobile inspired and integrated desktop experience for hip tech-savvy consumers and forward thinking modern business users."
Fedora Workstation = Core + Mate (Gnome 2 + Compton and/or Mutter)
Purpose: "Deliver the performance, reliability and stability demanded by designers, engineers, financial analysts, and researchers running large complex applications."
This way both use-cases can evolve to their full potential without any compromises or limitations.