Canada-based luxury residential and mixed-use developer Westbank, which has played a key role in the Four Seasons Oahu at Ko Olina Resort project since the start, has taken a diminished role in the development, the head of the master developer of the West Oahu resort confirmed to PBN Wednesday. The redevelopment of the former JW Marriott Ihilani hotel into the first Four Seasons-branded resort on Oahu, which was first reported by PBN, took a small turn after Nordic PLC Construction stepped in to…