I just received my copy, and while I haven't had much time with it, my initial impressions are quite positive.
I will say that this idea of developing the b1-knight to d2 is covered in the book, in chapter 4b, beginning on page 182. It's true that Ntirlis doesn't seem to say anything about the 3.Nf3 Nf6 4.Bg5 move order in particular, but I can't possibly see how playing 4...Be7 would lead outside of the scope of the book. There is also some coverage via the Colle move order.
One variation that I do wish had been covered, but which I can't find, is 5.g4!?. It looks ridiculous but has been played by some strong players (rarely):
If I recall correctly, it was also covered in Dangerous Weapons: The Queen's Gambit, so it would have been nice if Ntirlis offered a solution for Black here.
Stigma wrote on 12/22/17 at 14:24:57:
I didn't go back and look at the older threads. But doesn't 4.Bg5 h6 make a lot of sense if Black is a Moscow/Anti-Moscow player (like that Kaufman repertoire)?
Yes, you're probably right; 4...h6 should probably be the choice of a Moscow player. But I'm not sure what to recommend if Black wants to play the Botvinnik, and even a Moscow player might be out of their normal repertoire after 5.Bxf6 Qxf6 6.Qb3 or 6.Nbd2. Probably nothing too critical, but if you want to play the Botvinnik from this move order as Black, White can force you out of it.