the post office has utility even if the messages have very high latency.

also if this probe network reduces the transmission costs to normal terrestrial levels (and not requiring , say, a 400kw tx dish..) it could drastically increases the utility of the link -- and all of this without discussing how much bandwidth a link network across the stars might possess compared to our current link to Voyager..

(this is all said with the presumption of a reason to have such distance communications channels.. )