Given that the diameter of the solar system (to the point where interstellar medium meets solar winds) is about 0.0032 light years, I'd say we haven't really increased our interstellar exposure too much here.... (Actually, assuming Voyager can emit the same level of EM as Earth in your example, we've only increased exposure by 0.059% by volume, perhaps a bit more due to distance away from sun). It's only traveling at 4.57x10^(-5) lightyears/ year too, so ummm, I wouldn't hold my breath for new Alien friends?
I'd say Voyager 1 is only at the very beginning of its interstellar jaunt. The systems its course is projected to intersect may be among Sol''s neighbors but the distance to them is of a vastly different scale from well-known cis-lunar space, by a factor of 300K to the nearest ones. Your calculations should show this.
Purposeful interstellar travel is an iffy idea at best. But the astronomical distances which the Voyagers are transiting are not what intrigues me. It's the overbearing fact of our shrouded emergence in this universe which taunts us all. The fact that our existence on this low-observable planet (and of anything else in this sparse region of the Arm) is physically indeterminate from the frame of reference of any other star system. Due to physical c effects, the light of this fact has always been inaccessible to any would-be observer out there. We don't know how to broadcast a gravimetric ID signature, and our civilization's passive optical signature gets extinct at relevant interstellar distances. Philosophically, we may as well not exist to the cosmos, because what we know of ourselves and of events within our Locality has been forever circumscribed to us.
That is, until possibly now. For today, the probability that our existence just might be discovered and ontologized by some extrasolar civilization at some future time, has nudged from zero to something approaching zero. This is a big jump philosophically, because no non-fiction narrative of the human race could encompass the probable historicity of such an event until perhaps now.
That's if history is indeed made possible, for this fuzzy claim comes with a boatload of caveats.
One is whether Voyager 1 is actually free of both Sol's gravity well and heliosphere. Or whether it will not be wrenched off course or obliterated by some intercepting Oort mass before its time. Or if mythical aliens even exist within observable range of its trajectory. And if such mythical alien observers would have the technology to discriminate and acquire an object approaching at near-relativistic velocities against the background of the ecliptic. Or whether the interstellar medium exists and behaves as described by astrophysics, if even axiomatic constants like lightspeed do not vary referentially through spacetime - and our spacecraft are not affected unpredictably.
Still, but for the last absurd but not totally impossible scenario, we have a non-zero probability of an escape event for our species free of prior scope. Even if only in name.