According to the OpenGL 3.3 core specification, it should be possible to bind a completely empty VAO (with all attributes disabled) and render with it with glDraw*Array. The vertex shader will get default values for any numbered inputs, gl_VertexID will be filled in, etc.
According to the OpenGL 3.3 compatibility specification, it is not possible to do this. Compatibility specifically says that something must be bound to attribute 0 or glVertex, or rendering fails with GL_INVALID_OPERATION.
Both AMD and NVIDIA get this wrong, though in different ways.
On AMD, it fails in both core and compatibility. On NVIDIA it succeeds in both core and compatibility.