It's still a separate factory making separate drives. This line even uses a different storage controller. But this is also true for luxury ranges, in general, so you may be asking for too fine of a distinction. (Their usual luxury range is the WD Red, however.)
They try to get rid of the HGST brand but failed. And had to go back to HGST branding specifically for HDD coming from the acquired HGST Factory.
i.e AFAIK HGST is still HGST.