Earlier quoted context omitted.
Not likely. Even traveling to a planet as "nearby" as Neptune by conventional means would take 12 years. Hardly within shooting range, and who knows whether our civilization will survive long enough for us to make it to even the edge of our solar system. And the OP was referring to a nearby star system, within "sublight year" range. Even < 1 light year could mean very, very far away.
They are referring to a single system... Here is the quote: >> And to think that there is likely an Easy Mode system out there. >> A habitable planet on the low end of the mass spectrum needed for a stable atmosphere with other habitable planets in-system. And all that close to another star with habitable planets, possibly in the sub-lightyear range. Yes, they mentioned another star system as an additional point, but…
You must be joking, or you are completely unaware of Tsiolkovsky's equation.