Starting today if you buy a Talons of the Emperor Box set from Games Workshop, or even bought one previously and you still have your proof of purchase, you get a booklet containing rules for all the units in the boxset. This means you will not have to own a copy of the Index: Imperium 2 to use the models in the box.
Interesting that they are doing this. My thoughts are that this means we will not be seeing any codices for some time for these forces, and complaints of having to have Indexes, plus Codices, and even Forgeworld books to field an army may be starting to weigh in. Even if it's not, this is still nice that GW is adding to the box set.
via Warhammer Community
https://www.warhammer-community.com/2017/08/08/talons-of-the-emperor-free-booklet/
"From today, when you pick up your Talons of the Emperor box, either in-store or online, you’ll also get a booklet containing rules for all the units in the box for the new edition of Warhammer 40,000. With all the datasheets and points inside, this means you won’t even need a copy of Index: Imperium 2 to use your models."
"If you’ve already picked up your Talons of the Emperor box, there’s good news for you too: so long as you have your proof of purchase, you can claim your free booklet by getting in contact with your local Games Workshop customer service team."