Organisations sometimes change name: It would be nice if I could trace "previously known as" and "subsequently known as" relatiohsnips between organisations.
Taking this a step further, full Machinery of Government changes would also be good ("merged with", "split from" etc). The temporal scope of these MoG changes is also optentially interesting.
When the organisation-graph changes, who has reasponsability for the former-organisation's data? If we can track the MoG changes, we have enough information to start figuring that out.