Many of them have added DirectX backends in the mean time, and they will eventually had to either rewrite or contend to use OpenGL on DirectX 12 work Microsoft is doing.
The old ICD interfaces that OpenGL drivers rely on, might not be around forever, and so far Windows doesn't support them in sandboxed processes.
The old ICD interfaces that OpenGL drivers rely on, might not be around forever, and so far Windows doesn't support them in sandboxed processes.