Ignore the issues of dust on the way and the minuscule data rate. The real problem is that your probe, having no way to slow down, is going to blow through the

Ignore the issues of dust on the way and the minuscule data rate. The real problem is that your probe, having no way to slow down, is going to blow through the target system at 0.2c, meaning it will pass across the entire system from one side to the other in a few hours and be gone. There's no time to find planets and pan to track them -- assuming the "chip sized" device has the ability to orient itself in any case.