Well, it is also known as 'Classics 2.0', even Hasbro called it by that name more than once. They just keep the official name to 'Universe' so they can slot in a few cute oddities here and there, like the odd Beast Wars or Armada figure.
As far as what fits in to a collection as being part of the 'classics' line, I guess it's all a matter of taste. I have an Energon Downshift filling the role of Wheeljack quite admirably, for example. Soundwave is represented by either Cybertron Soundwave Titanium Nappywave (Crud, but more in tone and scale with the regular classics than the larger and more 'severe' Cybertron offering...). The fact Hasbro released a Blaster repaint of the Cybertron Soundwave ratifies it as a legitimate Classics figure, IMO.
I bought a Cybertron Metroplex for my kid's Christmas present yesterday ($50 FTW) and I think that could quite easily pass as Classics Metroplex with a few small paint modifications, same goes for Energon Omega Supreme.