According to the spoilered GalNet Article, there are Emancipation centers in Cemiess, Ngun, and Eta Horologii, however it seems like none of these systems actually want imperial slaves. Naubakht city doesn't list them on the marketplace, and Mackenzie Relay has 0 demand for them.
I think that's because it's essentially charity, and there are a whole lot of players who are doing it. However there is one system in the area with cheap enough imperial slaves that you can make a small profit.
Good stuff! Glad there's a group out there! I've just been selling to those systems, and I believe the developers will release information about how it all went after they do the numbers.