Inclusion debates/Knock! Knock! Who's There? Joke Book

So, very minor discussion, and I admit that I'm not the best person to start this off. Knock! Knock! Who's There? Joke Book has just been released today and is the sort of thing that normally would not be narrative, and so would instantly fail rule 1. However, the author has tweeted that they specifically used a loose framing device for the book wherein characters were trapped in a joke book to make it narrative so it would "technically count as a valid narrative source according to @TardisWiki". I have not read the book, I don't feel like spending money on a book that just came out the day of to see what sort of narrative content we're missing out on (I assume not much), and I can't even do so yet, being a US resident. So someone other than I would be best placed to comment on this.

With that said, I don't immediately see an issue with this being valid, however, due to the nature of the topic, a book that would normally be non narrative, having a very loose narrative placed onto it specifically to work around our ruleset into it being a valid source, I felt it merited discussion.

Potential topic for discussion: Farnell is not actually listed as the book's author, as this is a children's joke book, just the publisher is listed instead. Can we actually be certain he wrote this?