>>58243460Fairly or unfairly, TPCi needed to destroy Ash-Greninja because it was made by employees lower in the totem pole in the corporate ladder. It may have been approved of its creation at that time with no input from TPCi or Gamefreak but it's greatest sin was that people actually liked it, fans in general even if they complain about Greninja not having Mega at the time of its release. It even made it into the games long after the anime it was in was airing
It's a Kemono Friends situation all over again, where Kadokawa punished the director of the anime for making the dead IP super popular and making a BS reasoning that he didn't get permission this-and-that. It's Japanese corporate culture. Instead of simply appropriating Ash-Greninja it needed to be destroyed. It's also the reason why the form was merely an illusion in the last Ash anime series.