Not always the best source but:
https://www.engadget.com/2018/05/21/amazon-in-talks-to-revive-the-expanse/
"Amazon has the on-demand streaming rights to
The Expanse in North America. However, its arch-nemesis Netflix offers the show beyond North America and New Zealand. It would either have to find a way to take greater control of distribution, limit new seasons to just a few countries or accept that it would support a competitor."
But then again what is a good source anymore. Funny that the Hollywood Reporter uses the headline "'The Expanse' Revived for Season 4 at Amazon" but then the first line says "Amazon Studios is in talks to revive one of CEO Jeff Bezos' favorite properties."
There is a big difference between "in talks" and "revived"