After the show was canceled by Sci-fi, Amazon Prime picked it up for Season 4.
In May, 2018 Syfy announced the cancellation of The Expanse making this the series finale. However, the show's creators said that they would be shopping other networks to continue the series.
The title of the episode, Abaddon's Gate, is also the title of Book 3 in The Expanse series, of which the latter half of this season is based.