Which would explain what ccvi said?
The patch or the game installer will not invoke DX11. They have not been able to for several updates now. If you installed an earlier version, it created a desktop ICON for DX11 and that ICON will still be there, no matter how many patches we do.
Regardless, the question at the end of the installation (patch or full install) does not have the capability to as to run the DX11 version, and has not have that capability for several patches.