This is ridiculous. Set aside the (incredibly optimistic, to be charitable) thinking that is going into the acceleration of these probes. The astronavigation itself is hugely questionable, especially with probes that aren't big enough to hold the kinds of equipment necessary to detect bodies that would perturb the trajectory, let alone make adjustments after encountering these.
I don't think people realize how mind-bogglingly, incomprehensibly HUGE space is. It's BIG. Like think of the biggest thing you can comprehend, and it's not even the size of an atom in comparison to even "short" distances in space.
Something I would point out is that this is more of a conceptual proposal than something real NASA is planning on doing. This mission as described here will never happen. With that said it’s still a useful exercise because we will do space probes to Alpha Centauri at some point and doing a pretend proposal for one and solving all the problems that come up when you try to do so will help make it feasible to actually do that type of mission in the future eg. The Europa Clipper or a lot of the other space probes we’ve done.
I don't think people realize how mind-bogglingly, incomprehensibly HUGE space is. It's BIG. Like think of the biggest thing you can comprehend, and it's not even the size of an atom in comparison to even "short" distances in space.