it could be that, but I also think that no expense is too expensive when it adds so much visible storytelling, just hearing about Shiro and his daughter would make the novel feel out of depth (even though it's already great as is)
I think you could achieve the same depth from just writing a conversation between MC and Shiro. Or even Shiro and Artemesia. I imagine an AI you're about to delete anyway(though Shiro presumably did not know she backed herself up) makes for a great therapeutic confessional.
You can get all the character development and pathos and good stuff without buying that model.
I dunno how buying Daz models works exactly. Maybe he intends to use her for a future project, if that's allowed? If so...okay. Maybe she was introduced just as a background NPC. But Occam's Razor says she has a bigger role to play in this story, and with so little time left before the finale there's only one role that makes the most sense.
She's too perfect as a convergence of motive, means, and opportunity. Too many clues have been sprinkled and the payoff of a well written story should always make sense. She makes sense.
The Roundhead Johnson/Jar Jar Abhrams school of thought in Story Telling...'Subvert Expectations for the sake of Subverting Expectations' needs to go the way Lily Phillips ability to pairbond.