Aliens could use this method to keep data transfer at a reasonable pace across the light years. However, the bottleneck for that type of transmission technology is light interference from the local star, which would outshine the pulsing beacons. So the civilization would probably put such a beacon in some sort of interstellar orbit - or at least very far on the outskirts of a star's system itself. That way it wouldn’t need to compete with the light coming from the star itself. SETI’s current astronomical surveys are effectively blind to that exact type of laser communications relay