At the moment it seems that certain types of boards e.g. Sales CRM template boards can’t be moved to other workspaces. (not sure if this is it for all templates).
This is very frustrating as during the development of a work process we might try different stuff to get the workspace working as intended. This means that at the end of the process we notice that certain boards etc. don’t belong to a specific workspace but would suit better into another or its own altogether.
TL;DR: Make it so that admins can move any board to any workspace without restrictions.