That we would receive a signal with the radio telescope discussed here would pretty much demand either that they make tremendous use of a very specific form of

That we would receive a signal with the radio telescope discussed here would pretty much demand either that they make tremendous use of a very specific form of propulsion, or that they are putting a substantial fraction of their available energy into contacting civilizations of precisely our technological level. There's no thought that we'd pick up their radio chatter between themselves- we couldn't pick up Earth's radio noise from that distance, and we're only getting quieter as our technology becomes more effective. Aliens in the business of contacting emerging civilizations must find themselves with an interesting tradeoff between transmitter power usage and contactee technology level- at a guess, it would be exponentially more expensive to contact species earlier on in their development. We may still just not be far along enough that the cost-benefit ratio makes sense to talk to us.