The master player in one type I was talking about is someone like MJ. He pushed the expectation so high in both quantity (from data's point of view) and quality (all those master level moves only rooted from unreal fundamentals). There is basically zero chance to have someone better than him in the short and mid run. And the league had to change how the game is played to create space to expect another master player in another type. In this process, before the true master player emerges and matures, there is also some time for the fans to speculate who will be the master in each generation of players till that final one arrives. In short, better versions of a certain type of heroes keep coming and attracting more fans and pushing the expectation higher. It somewhat resets the product and let the new dynamics evolve so that it keeps the cashflow flow in strongly and can last for quite some time.

Of course, just my observation.

edit: added the product and dynamics analogy and corrected grammar.