From what i understand, the cloth phys code is 15+ years old, any large change like GPU computation is impossible as is.
The only way i see GPU cloth working is with a new code (discussed on another thread),
Vivace implementation for fast cloths and soft bodies simulation - Blender Development - Blender Developer Talk
GSoC 2020: Soft Body Sim - Discussion and Suggestions - Blender Development / Summer of Code - Blender Developer Talk
Other than that, we can only wait for someone to implement this, but it would have to collide with mantaflow, cause its pointless if it didnt play well with mantaflow as both are physics based and would logically interact with one another