The worst problem that can occur is that someone will enter a
reference to their person/role object just as we delete it. However,
as we are only deleting unreferenced person/role objects, the time
needed to re-create them is minimal. We suspect that a very large
proportion of the unreferenced person/role objects that we will be
deleting are abandoned objects that are no longer used.
A bit of thinking can come up with some scenerios that might be
worse(*).
I definitely think any minor problems are more than outweighed by the
removal of unused personal data!