Disclaimer: The topic of this thread was first mentioned in the spoiler thread but it has no relationship to the chapter spoilers, and I would prefer discussion on it took place in a more persistent place, so I created this thread.
I have seen several people express the desire for Zoro to have a clean defeat in the upcoming Onigashima raid against his 1 vs 1 arc opponent (presumably King or Who's Who) when they fight. Zoro would then later defeat said opponent in a subsequent battle. Those who expressed this desire have said that it will make Zoro's fights less boring and would help him grow as a character.
I think the desire is a bit misguided. I'm not sure there's any meaningful lesson Zoro can learn from a defeat against a stronger opponent. In his battle with Mihawk, he already learned the vastness of the world:
That defeat made Zoro insecure about his strength and drove him to desire to be extraordinary:
He has already faced (likely) the strongest opponent he would ever face and acknowledged his inferiority. He abandoned his pride and begged Mihawk to train him.
After his loss to Mihawk, Zoro swore (upon Wado Ichimonji, his only memento of Kuina) to Luffy that he would never lose again. The vow was acknowledged by Mihawk himself:
This promise was so important that the chapter was named Oath:
While it is true that Zoro has had subsequent defeats and losses (Enel, Lucci, Borsalino and the Yeti Brothers come to mind as plausible losses), none of them were in straight 1 vs 1s against his arc opponents, and none of them were swordsmen. In short, none of them were duels. Zoro's oath can be understood as being in reference to duels with other swordsmen (he just lost a duel to Mihawk and promised he wouldn't lose until he faced Mihawk again), and in that respect, he has held up his promise. A clean defeat by King or Who's Who will cause Zoro to break this most solemn vow. His oath to Luffy is one of the three most important character defining moments for him (the other two are the Thriller Bark scene and when he bowed his head to Mihawk to ask him for training). That vow is a core component of his character.
To get defeated by another swordsman would break that vow, it would severely undermine Zoro's character. And for what? To make his fight less "boring"? To add some vague sense of excitement to his battle? To generate fake tension? Instead of adding depth to his character, a loss would only serve as regression for Zoro. Would you really rather Oda undermine Zoro's character for cheap thrills?