Lance Reddick, who passed away recently, has been published by Guerrila Games. He played Sylens in Horizon Zero Dawn and Forbidden West, and he was a key character in the series.
The message from Guerrilla, which was first mentioned in the following tweet, is this:
Sylens was played by Reddick in Horizon. This is a character that often remains hidden in the story, but has always been important to the overall plot.
Alert: Spoiler alert
We can conclude the series Horizon Forbidden West by saying that the character will have more space in the future. Guerrila Games will therefore have to continue on its own path without the support of Reddick.