Why it's on the list: Yes, this is just a dumbbell press with some rotation added in. Why give it a separate callout? Because the namesake of the move was definitely onto something!
Research has shown that the staple move of old-school muscle-building programs like the Blueprint to Mass hits both the front and medial delts more than other dumbbell press variations. Plus, many lifters simply find it more friendly to their shoulder joints. That's a big one-two punch.
Arnold Press Variations for Shoulder Development:
In your workout: These are great first in your workout, or second after a more basic overhead press. Consider pyramiding up in weight and down in reps for 4 sets of 12, 10, 8, and 6, like in the 3-Move Shoulder Builder workout.