I was pointing out the generalization. That phrase seems randomly taken out of context, and to me simply means that an Alien EU exists.
As far as being a declarative statement about canon, no. It says nothing about how coherent it is, if there are contradictions, what these contradictions mean to story continuity, etc...
Don't try and make it mean something it doesn't. It's just a line on a DVD special feature, probably said in passing.