Rights restriction reason not appearing in `rights` search field

[Conal-Tuohy]

The rights Solr field contains a licence identifier and a short description, but is empty of a reason or justification for the selection of that particular licence.

[Conal-Tuohy]

This query produces zero results:

PREFIX crm: <http://www.cidoc-crm.org/cidoc-crm/>
SELECT ?reason
WHERE {
  ?reason crm:P2_has_type <http://vocab.getty.edu/aat/300404457>
}