alt Hacker News175 years isn't a lot of time when we speak in humanity's time scale. We've been around 200,000 - 300,000 years.
That alignment will happen many more times in the history of humanity. That is to say, I don't know if a spacecraft to overtake Voyager will be launched on the next alignment or one 10,000 years from now, but it doesn't seem unlikely to happen.
If humans survive 1000 years I can’t see any way we haven’t populated the solar system and can build probes which travel far faster than voyager, including self sufficient asteroids
Once we leave the solar system in a self sufficient way I can’t see any event which would cause a species level extinction