Who told you that? That's like saying you can install a car alarm by tapping into any wires on the factory harness.

All vac lines are not created equal, and they aren't attached to the same locations. There are some on the intake manifold side of the throttle body, some on the valve cover, you get the idea. You want the boost gauge to come from the intake manifold somewhere, the BOV to come from the intake manifold somewhere, and the wastegate to come from the piping between the intercooler and the throttle body. You can also come off of the turbo side of the piping but then the wastegate won't compensate for pressure drop across the intercooler.