I'm sorry, but this is horse crap. How many times has this "set it and forget it" excuse been trotted out in order to justify changing the entire core of a WF? Also why is it so unevenly applied?
Example: It was used to justify taking a collective dump on Ember's head, changing her Ult without really making her other abilities more robust. I almost never see Ember anymore, because this nerf was slapped on as a band-aid and she was never really improved/balanced past that. While I agree her four needed to be changed, what was done to her made her damn near unplayable. Now let's look at my favorite frame in comparison: Ivara. Will her stealth be getting a nerf, based on the "set it and forget it" idea? I can literally put her 2 on, and then go get a snack and take a bathroom break. I have timed her stealth (with my current mod set of course.) and I can stay in her prowl from anywhere from 10-15 minutes. Is this not the personification of "set it and forget it?"
Wukong's entire gimmick is never dying and hitting things with sticks. By completely changing Defy, you are completely changing what Wukong is as a frame. Let me ask you something: Has Wukong's defy ever been truly broken? Certainly not in my opinion. In fact you said yourself he is one of the least used frames. If his defy was ever truly broken, this rework would have happened a long time ago, and he would be close to the top of frames used. In my opinion defy is also in no way "set it and forget it." You have to manage when to have defy on, because it drains a lot of energy, and if you want to use his stick that drains even more. There's interaction, because you have to make the choice of when it is advantageous to have defy on.
If this "set it and forget it" excuse is going to be used, it should be equally apply to all frames, not just a few because you felt like changing a few things. If you're going to change a frame's entire concept, don't and instead make a new frame that could fit that concept. I'm tired of seeing reworks that boil down to "Ok we don't like thing, so we change thing and not really give a darn about how this changes the frame." Wukong's Defy does not need this kind of a nerf, and in your effort to make him more "playable" you might just kill off any following he had to begin with.
I hope you take feedback like this to heart, and really give the rework a good hard second look because of it.