The entire premise is rather bizarre.
"Let's send out probes that make probes that send out more probes until we've covered the galaxy!"
"But... why would anyone do that?"
It seems obvious until you think about it - and then it stops being obvious.
So you cover your galaxy with probes that keep sending probes back and forth. So what? What have you actually achieved?
If you assume massively superhuman intelligence, what are the odds there are more interesting goals for a civilisation to aim for?