Act prep guide 2018

There’s a new prep book by the act coming out on May 30th and i was wondering if i should buy it to study for the September test or will it be the same thing as the 2016-2017 guide?

http://talk.collegeconfidential.com/sat-act-tests-test-preparation/1987846-new-act-prep-book-2018.html#latest

Quantum did some good research.