Holden used to sell re-badged Opels (just like Vauxhall in the UK), and Omega and Commodore were Opel models in the past. The old Holden Commodore (80s-90s) was exactly the same as the Opel Omega.
So nothing new about cars bearing the name Commodore (legend goes that Jack Tramiel thought of the name Commodore when he was riding in an Opel Commodore taxi).