That is a short oil change interval, especially if a full synthetic oil is used. Possible reason is Nissan has had issues such as sludge build up. Also, if the motor is turbo charged the turbo might run very hot and need good fresh oil to keep from burning out the bearings in the turbo.
If the oil changes are free I guess no harm no foul. If I was a dealer giving free oil changes for a year I’d go with less expensive oil than Mobil 1. You need to see if this free oil change using Mobil 1 is a dealer standard policy for all cars, or something unique to the model and motor in your car. If not a dealer SOP then I’d be on top of oil changes in this car once your free year of oil changes is past.