We recently found out that Game of Thrones season 8 will premiere in the first half of 2019, and now HBO Programming Chief Casey Bloys has disclosed new snippets for the upcoming season to EW.
Bloys said the episodes in season 8 will not be 2-hours long, according to his knowledge. He also shared that he thinks the final season trailer will launch in 2018, but he has not been told specifically when it will.
In terms of the possibility of any more Game of Thrones prequels besides the one announced that is being written by Jane Goldman and George R.R. Martin, Bloys confirmed that is a no for right now.
Source: IGN.com HBO Confirms Game of Thrones Season 8 Episodes Will Not Be 2-Hours