Destiny Unchain Online: Kyuuketsuki Shoujo to Natte, Yagate 'Aka no Maou' to Yobareru You ni Narimashita - Vol. 10 Ch. 89 - Reincarnation of the Firs…

[ThatRabidPotato]

nope...
in the novel

They (Crim/Kou Parent) had developed the Cradle as a way to evaluate Kou’s body in depth, and Destiny Unchain Online was built as a playground for Kou’s consciousness while her body was regenerated properly.

But neither parent had expected that the process would also turn Kou into a girl

Flat out not true, his mom is anticipating the sex change from the moment of her first appearance in Chapter 5. This was deliberately planned by both of them to swap his sex without his knowledge or consent.