I totally headcanon MMZ Zero being voiced by Lucas Gilbertson. I think it fits and I don't see an in universe reason as to why his voice should change. Btw Lucas' VA has improved a lot since the X series, and I know that because of Terminalmontage. I have this recurring joke in my head involving Zero going somewhere in the base and seeing something like everyone in the base playing randomized card games with randomized rules, and his response is confused silence and then "what on earth is going on in here on this day?" I thought that was funny.