People are missing the point. The ONLY reason for the forced relocation was that the Sona were greedy and selfish. They didn't want to set up a colony and they wanted the youth effects NOW. And they were ready to harm and kill the inhabitants for it.
The end of the film never suggests that the metaphasic radiation is not used by the Federation. The end of the film only shows that the Baku stay and the Sona return home (which emphasizes the idea that the relocation was absolutely unneccessarrrry to begin with).