It's a United Empire-specific tech in the Empire Building tree, and it says that unlocks new government types. Except as far as I can tell, it doesn't. I have the same four government types that I've had since the start of the game (Federation, Democracy, Dictatorship, Republic). 

Is it a typo? A bug?

Those are the only 4, but you aren't allowed to switch before researching the tech. It doesn't "unlock" new types by creating new ones, but it gives you the ability to choose from those 4 instead of being stuck with your original.

Ah, I see... thanks!

Another question: is there any difference between UE version of Xeno Antropology with the vanilla version? As far as I can tell, it seems like the only difference is the additional flavour text for Governement Diversity.