Well the basics underneath Tupelo are cryptographic signatures and an immutable chain we use call a ChainTree (which is per repo), so in theory this could work between two people so long as you trusted each other's signatures. Using the Tupelo network provides trust for the specific name, as well as prevents conflicting updates to the same repo.
It's a very interesting idea though, would love to hear more. Feel free to drop by our gitter: https://gitter.im/quorumcontrol-dgit/community