I try to avoid overgeneralizing in answers, but in this specific case, I'm pretty comfortable in saying that no warrior has ever been trained to deliberately expose his back to an opponent during hand-to-hand combat. Your assumption that it's just the choreographers trying to spice things up is correct.

In the context you're talking about, no, absolutely not. The classical Greek military formation was the phalanx, which required lockstep unity among its soldiers. Their primary weapon was a long pike, and they carried large shields which protected both them and the man to their left. In such a situation, not only would such a spin attack be useless and dangerous both to the individual and the unit, it would probably be physically impossible given the confines of the formation.

Roman infantry formations were less rigid, but still demanded a high degree of unity, and close-order drill was the norm. Classical battles simply didn't involve freewheeling individual combat- strong formations and unit cohesion were key to success.

could you post an example video ?

The earliest western martial arts manual is MS I.33, which dates from the 1300s. Before that, there's no good comprehensive source on fighting techniques. So, we can't say for certain that nothing like this was ever practiced.

What we can say, is that in the Western martial arts traditions that we do have (from 1300 on - I.33, Fiore, Ringeck, Talhoffer), spinning moves like that are not used.

A half-turn away is fairly common (known as "refusing" your body), which you can picture if you imagine taking a batting stance towards your opponent, and then shifting your weight onto your back foot, but never a complete turn away. That's a good way to get dead.