With the stories all quickly coming to a close, they believe that fewer episodes would serve the narrative better, rather than attempting to stretch them out simply for the fans.
From Casey Bloys’ comment, it seems like HBO is happy to produce as many episodes as Game of Thrones needs to fully complete the story of Westeros.
It’s a decision that seems to both please and disappoint the massive audience that has been following Game of Thrones since its first season in 2011.
But Game creators/producers David Benioff and D.B. Weiss have been saying for quite some time that final two seasons would be shorter than the previous six.