After having fired the co-creator and star from the show, supervising producer Sydney Ryan explains why Solar Opposites season 4 didn't opt to cast a Justin Roiland soundalike. Roiland led the cast of the first three seasons of the Hulu show as Korvo, the alien scientist and leader of the family, though was dismissed in early 2023 after the reveal he had been charged with felony domestic abuse. Roiland was also dismissed from fellow Hulu animated show Koala Man and Rick and Morty, the latter of which confirmed plans to recast him as with Solar Opposites.

https://screenrant.com/solar-opposites-season-4-justin-roiland-recasting-soundalike-no-explained/