I had a 2004 vfr800 with linked brakes and no abs. Honda's linked brake system had dual master cylinders at both ends. For front, one at the handlebars and one on the front fork. when you applied the hand brake, the front brake would apply force to the rotor and by gripping the rotor the mechanism had the add on master cylinder and applied force to brake line going to the rear brake. If you were stopped, the front only gripped the rotor and no force was applied to the rear wheel.
The same type of setup was on the rear brake so using the rear brake pedal would apply force to the rear rotor thus making the mechanism push on another brake cylinder which applied force to the brake line to the front brakes. This is a mechanical system that worked quite well.
ABS is an electronic system that senses wheel lock up and release the brake of the locked up wheel so it can continue to roll thus keeping traction and thus better control.
Since both wheels have a sensor they are linked to a central control unit.
To prove a point, lift the rear bike with a stand or a wheel chuck that has rollers. Now squeeze the front brake as hard as you can and see if the back wheel still rotates freely.
If it does, you DO NOT have any kind of linked system and should always use both brakes to stop. Then go tell your dealer they are full of _ _ _ _ If I am wrong, you can tell me that too. I have been wrong a time or two in my life but don't think so on this.