However, the main question is:.... can a previous ( or two series before) series speaker cable sound better than a new improved version.??
Many folks make the assumption that newer = better, which is a common misnomer. Companies introduce new models of anything to stimulate sales. They know their clientele well enough that their customers will demand the latest and greatest. LOL!! Thereby feeding their coffers and stimulating their business. Companies come out with new models when they want more money....it's not because they have come across some revolutionary discovery, despite what their marketing folks will have you believe.
That is one of the reasons that tubes and vinyl remain so popular today, because newer is not necessarily better. Different maybe, better, maybe, worse, maybe.