Coincidentally, I received one this week for my 10 night at Jambo coming up in January. I did not receive one for my 4 night stay the Poly Tower, which will be my split stay.
I asked a friend of mine for whom I booked a 5-night stay at Jambo House this past October. He did not receive the booklet.
So I was thinking maybe it depends on the length of the stay.
The booklet is kind of, for lack of a better word, redundant as I've stayed at AKL 10 times in the past 15 years, while the book is obviously for first timers.
And as others as noted, getting the booklet seems to be hit or miss.