This is because it is (or rather was) Versus; a game that was designed to be different from the main entry XIII in every way including the reality thing and the combat style. With no release date in site, Square Enix can just revise the whole combat thing and that's what they state at the beginning of the gameplay video. They just needed to show whatever they had. I don't expect this to be released anytime soon,
No foreign sky protected me,
No stranger's wing shielded my face.
I stand as witness to the common lot,
survivor of that time, that place.
- From 'Requiem' by Anna Akhmatova







