Pretty sure that is still not the meaning of refactoring. As I understand it refactoring should mean no changes to the external interface but changes to how it is implemented internally.
Functionally, I suppose it's the equivalent of upgrading an ID field that was originally declared as an unsigned 32 bit integer to a wider 64 bit representation. We may not be changing anything fundametal in the functionality, but every boundary interface, protocol, and storage mechanism must now suffer through a potentially painful modification.