I think it creates them anyway. Otherwise it would first have to check all vertices is they are used in any triangle before it could start adding them to a surface. I'd rather think it will read the vertices, add them to a surface right away and finally create the triangles described in the tris chunk. So it may leave it up to an external mesh optimize function to wipe out unused or double vertices.
Of course I could be wrong, you can check this out easily by loading the mesh and then watch CountVertices.
Of course I could be wrong, you can check this out easily by loading the mesh and then watch CountVertices.