It’s anyone’s guess right now. Until we know for sure, I would take a hard pass on purchasing test prep books. I was in Barnes and Noble yesterday, and it would appear everyone is sharing that sentiment.
Sign up is in October, so we might get some hint at that time. Although I wouldn’t be surprised if registration gets pushed back, both so College Board can get a read on how things are going and so they can get a handle on the fall SAT registration, which is still a mess.