They probably can afford self-reflections in menus and photo locations so I would not discard the video by that detail. Overall it looks very "GT".
That would require them to implement a completely different rendering approach for car reflections for different modes though, which I don't see them doing. If they're using screen-space to get self-reflections rather than their old way of doing pre-baked cube maps then it should be applicable for gameplay too.
The leaked static renders or even the garage scenes in the GTS trailer don't exhibit any new form of reflection rendering and completely lacks self-reflections, which makes me think the Alfa Romeo clip is not related to GT.
It does look GT-esque, but I'd say the car shaders and lighting actually don't look that much more impressive than GT5.