[zythyx]

Microsoft could have used any dataset for their blog, they could have even chosen to use actual public domain novels. Instead, they opted to use copywritten works that JK hasn't released into the public domain (unless user "Shubham Maindola" is JK's alter ego).

[bossyTeacher]

Rowling is known for using pseudonyms. Maybe she got tired of writing and decided to break into LLM tech.