So far I've found this the most helpful.
To my knowledge it doesn't look like there will be any issues as long as we:
Upgrade the server first
Either - Upgrade all desktops at once OR let users upgrade in a self service fashion. This would mean any compatibility issues within the team can be resolved by simply having the rest of the team upgrade
Ensure publishers have existing copies of their workbooks available. - This avoids issues with the server upgrading a workbooks extracts to hyper or other people publishing their content in a newer version
The above usually seems to be the case anyways. I haven't known many users to trust the server with the only copy of their work
I'm going to run under these assumptions for now but let me know if I missed anything.