When the unit is complete you gain that model type and name (until you upgrade it) and increases your own practical experience (which will assist your own research efforts in the future). This costs money but can be money well spent. Of course, these, as well as expeditionary forces retain the model & tech names of their origin, until upgraded.
That doesn't means I own this model. I still need to research if I want to build another, am I right?
Another question is how could I upgrade expeditionary forces?
Thanks