Horizon MMO reportedly planned for partnership with NCsoft
As reported by Korean news site MTN, and as translated by Eurogamer, Sony and publisher NCsoft have "tentatively agreed to pursue a business partnership in which NC will create new games using Sony's promising game IP", starting with a project based on the same world as seen in Horizon: Zero Dawn and Horizon: Forbidden West. The project is supposedly still in very early development and has as-of-yet to be officially confirmed.
NCsoft is perhaps most well-known for publishing the popular MMORPG Guild Wars 2; so the assumption appears to be that the title would likely fall under a similar umbrella. Previously Sony confirmed its desire to pursue multiple live-service game releases in the future, and a licensed Horizon MMO would certainly fit in with that desire.
We reviewed Horizon: Forbidden West when it came out earlier this year, and came away from it feeling relatively positive about the experience as a whole. Whether or not this specific project ends up bearing any fruit, needless to say we're interested in seeing exactly how the series evolves with whatever comes next.