Within the code of Watcher there's leftovers (or base code) for something known as the Weaver, or VoidWeaver.
A devtools item for "weaverspot" appears between the devtools for 2 of the Primary Characters. As well as this, WeaverSpot naturally appears in Sunlit Port
Feather assets for the weaver
Here is an unused track: Weaver Energy
And also the code I found related to it. Here it appears in many of the room settings alongside the ST, Ripple Warp, and Flower Bed objects
Here it appears for the Map HUD code (code which shows you if a region is infected or contains ST) and is also where its referred to as VoidWeaver
I'm not particularly good at reading C#, and this was all I could find
I have many personal theories on what the Weaver/Void Weaver could be, but its clearly connected to the next Watcher update and will definitely be a key part of future plot/lore