This is a silly counterexample - why would we launch them that far apart? It’s a terrible idea for multiple reasons. We’d want them close together, with some redundancy as well, in case of failures.
What dish size would be required for a “cylindrical/tubular mesh” of probes, say, 1AU apart (ie Earth-Sun distance)? I’m pretty sure that would be manageable, but open to being wrong. (For reference, Voyager 1 is 169AU from Earth, but I have no idea how dish size vs. signal strength works: https://science.nasa.gov/mission/voyager/where-are-voyager-1...)
Light year is 63,241 AU. That means tens of thousands of relays. It would super expensive and super unreliable. The other problem is that achievable speeds are super slow, Voyager is 25,000 years per light year which means that would wait 100,000 years for relays to Alpha Centauri to be possible.
Much easier just to send probe with large antenna or laser, and make a large antenna at Earth.
Starlink has 10k satellites as per this Month. 60k doesnt seem unreasonable?
Starlink has a use case.
At Voyager 1 speeds, it'll take 70,000 years for a probe to reach Proxima Centauri. So you'd just be launching a probe a year for the next 70,000 years to create a temporary chain on a course to fly by one particular star. And for what purpose? Okay, in 70,000 years, if everything works out as expected, we have a chain of probes on a course to fly by Proxima Centauri. What problem does that solve for us ("us" here being whatever is kicking around on Earth after a period of time 5x that of recorded human history thus far).