There are no native humans on Alpha Centauri -- any people who are being enslaved are
Unity colonists. What's more, the average
Unity colonist are people who grew up in a world recognizable to us; living in factions with strong ideological agendas is going to be as weird to them as it would be to us.
Given that, we have a moral duty to rescue as many of them as possible; what's more, on a practical level, increasing our population at the expense of factions who are likely to be our ideological competitors
now pays considerable dividends later.
If the Pirates are able to do this mission for us -- incurring the casualties and diplomacy hits for doing so, but gaining the salvage from hitting the "grotesque" factions -- that serves both our agendas.
As such, I can see cooperation with the Pirates, along the following lines:
- The Pirates transport refugees wishing to depart other factions to Warm Welcome, and affirmatively seek them out.
- Ships transporting refugees will be allowed to pass through Warm Welcome unhindered.
- The Pirates stop taking Peacekeeper prisoners.
- We provide the Pirates heavy equipment and friendly ports.
(Given that we have 3 Talents and 3 other colonists, this kind of arrangement, where a steady flow of immigrants/refugees comes to Warm Welcome fleeing perseuction, also provides thematic justification for the
POPULATION BOOM!! we should be undergoing right now...)