This object simply reports whether this router's OSPF implementation supports Opaque LSAs, the extensible LSA type used to carry auxiliary information, such as traffic engineering data, beyond standard routing LSAs. It matters as a basic compatibility check; before an admin enables any feature that depends on Opaque LSAs, such as MPLS-TE, they need to confirm this router actually supports carrying them at all. A router reporting false here would need a software or hardware capability check before any Opaque-LSA-dependent feature could be deployed on it.