I hear executive producer-showrunner Ryan Condal, working with author/executive producer George R.R. Martin, took a step back as Season 2 was being put together to take a big-picture view of the series, which follows Martin’s Fire & Blood, and figure out the overall narrative flow, including how to break up the stories season-to-season and what battles to include and when.
As part of that, I hear Season 3 has been mapped out and might be greenlighted, with HBO seriously considering committing to moving ahead with scripts, casting and a production plan as the network too is trying to think long-term instead of season-to-season.
With a portion of the plot originally intended for Season 2, including a major battle, moving to Season 3, I hear it is now more likely that the series would run for four seasons