[strike]The last I recall, the GPU's that came from Asus all head additional PWM fan headers, not RGB headers.[/strike] I think you're also misunderstanding/misinterpreting the concept of Aurasync on the board, there are RGB LED's on the board's underside and you can use it in tandem with Asus peripherals and components that have RGB on them + control them in one swoop using the Aurasync app.
Yeah the GTX1080Ti has one header for RGB.