I am thrilled to see someone talking about this book besides me!
For anyone unfamiliar with the book, neither the paleoartist nor the authors are claiming that these dinosaurs did look this way - only that these speculations aren't contradicted by the evidence that we have from the skeletons.
I think the illustrations of modern animals purely from the skeletons using the same conservatism as is applied to dinosaurs is even more striking than the speculations on what dinosaurs could have looked like: