It looks like the engine will use a 64 bit depth-stencil format which has 32bit depth and 8 bit stencil if that is supported on your device as DXGI_FORMAT_D32_FLOAT_S8X24_UINT. This is a DX11 feature. In that case your memory for your depth buffer doubles but you have the same functionality. Everything else would be the same. You would lose stencil support on older cards that don’t support this feature.
Edit: It appears that stencil is not directly accessed by the user. You would have to write your own code to use stencil so it looks like you would not lose any user accessible functionality.