Cutting the cord and Game of Thrones ending would be my guess for the drop. They are actually doing the opposite of pulling out of markets and are doubling down and buying out a lot of local partners in order to get HBO MAX to launch in markets like Latin America and the Nordics next year.
I guess things can change a lot in a couple of years. I understand the reasons why they are still beefing, but getting on Roku/Amazon Fire Stick would be a plus for them in the future as well.