Just like Cinemax, HBO dropped the whole section. On Reddit/hbogo someone posted this response from an HBO email.
Customer Support Response (06/28/2018 05:05 PM) Hello,
”Thank you for following up with us.
As the entertainment landscape evolves, we've decided to invest in programming that our HBO community desires. HBO has had a successful run with original series such as Game of Thrones, Westworld, Ballers, and Insecure, as well as strong current box office hits like IT, Justice League, and The Lego Ninjago Movie.
We appreciate your support for Late Night programming, however, audience interest is low. We hope you're as excited as we are for our upcoming HBO original programming.
If you have any questions, please reply back. We're available 24/7 to help.
Thank you, HBO GO Customer Support"
I'd just get Showtime. Their After Hours section has a lot larger selection anyways.