my guess is the contract for holo talents is no vtubing outside of the company, but streaming as a fleshtuber or having just a pic on screen is fine, and maybe they changed the contract for all talents at one point, which is my theory of why kson quit, so she could vtube as kson, also it isn't uncommon for vtuber companies to have different contracts than other entertainment companies, like production kawaii doesn't let you stream outside of the company period.