I would follow the owner’s manual recommendation and not change the oil until 12,000 or whenever the oil life monitor (OLM) indicates the oil life is less than 10%. The oil life monitor is a computer algorithm (program) that tracks engine usage and detects percentage points based on the time and temperature usage. For example, one cold start from zero degrees may deduct one point whereas it might take 1,000 miles of highway driving at a steady speed in 70-degree weather to deduct another percentage point.
Engine manufacturing and engine oil have greatly improved since you heard the oil should be changed soon after purchase. Now most vehicle manufactures are recommending the oil be changed about once a year or whenever the oil life monitor indicates the oil needs to be changed. The OLM also “assumes” the specified oil is being used, so always use Dexos approved oil in your new truck. Enjoy.