There is no confirmed release date for The Expanse season 7. No upcoming additions have been announced by Prime Video.
The service still lists The Expanse as a six-season series, with all six seasons available on the service.

The Expanse season 7 possible return
The previous mentioned situation has not changed into a confirmed revival.
Recent discussion around a possible return is largely coming from fans and entertainment coverage rather than an official production announcement. The final three books remain unadapted.
Any claimed Season 7 premiere date you see are false. There is currently no official Prime Video date to put on your calendar.
Why did The Expanse end after Season 6?
Season 6 was planned as the end of the television run. This was rather than the creators trying to squeeze the entire book series into one final season.
Showrunner Naren Shankar explained that there was no plan to cram Books 7, 8 and 9 into Season 6. Doing so would have required cutting a huge amount of story.
That decision also explains why the ending feels different from a typical series cancellation.
Season 6 covers the events of Babylon’s Ashes, the sixth novel. It has six episodes and ends with the Rocinante crew dealing with the Free Navy conflict.
The television story has reached a natural stopping point. But the larger book story continues.
What would Season 7 be about?
This would be interesting.
The next novel is Persepolis Rising. It is followed by Tiamat’s Wrath and Leviathan Falls.
The story jumps forward by about 30 years before Persepolis Rising. Humanity has spread through the network of worlds opened by the ring gates. The political situation is very different from what you saw in Season 6.
The final three books form their own major chapter of The Expanse. They are not simply three more books that pick up immediately after Babylon’s Ashes. The time jump changes the characters, the setting and the scale of the story.
That also means a future adaptation would not necessarily have to be called Season 7 in the traditional sense. A sequel series could make more sense, particularly because of the long time jump.
Would the original cast return?
There is no confirmed Season 7 cast because there is no confirmed Season 7 production.
However, the books provide a clear reason for the older versions of the main characters to return if the story is ever adapted. The later novels deliberately move the story forward by decades rather than continuing immediately from the Season 6 finale.