What does it mean that HBO’s Confederate creators “are not actively working on it”?

/Film

The alternate history slavery drama series from Game of Thrones creators David Benioff and D.B. Weiss has been met with backlash since it was first announced. The Washington Post reported this week that “though the show is still in development, the creators are not actively working on it, a person familiar with the process said.” Does this mean that Benioff and Weiss are too busy working on Game of Thrones to develop the series? Has it been put on the back burner?