This is all circular, they dropped him in n March- meaning they did not care if he left the organization or not. Frankly, Hiura is in AAA so he can get paid. There’s no question in my mind if he was willing to refuse his salary in order to leave, the Brewers would have released him.
The Brewers have been bad at DH, the gambled on Winker and lost, Canha hasn’t been good, etc. But in spite of the DH struggles they remain in first place and have been there most of the year. Are they more in first place had they called Hiura up, nobody knows.
With respect to the swing, making an adjustment is one thing, abandoning the swing that got scholarship, got drafted as a first round pick, and got 1000 PAs in the majors and trying to get back to the bigs with a different way of hitting is kind of nuts.