Funny, how I see it is that, if the ban was truthful, and correct, why the need to even publish a book to justify and have HHDL inaugurate it? If the ban was correct, shouldn't people all over the world just listen to HHDL and not counter it at all, since the ban is correct?
Publishing a book on Dorje Shugden, and I suppose the contents of which are to highlight that Shugden is an evil spirit, how he is not enlightened, how practising it will be harmful etc etc., goes to show that CTA/Anti-DS communities have to convince people that DS is as what they wrongly accuse him to be. If what they say were true, then everyone would've followed in the first place, and they do not have to go through these great lengths to prove otherwise.
On a side note, I'm glad to see the respect shown to His Holiness and how many people/sangha will be blessed by HH's presence in the talks.