If targeting GTH, the DisplayPort v4.0 core will not synthesize correctly in the non-project flow.
If a project is opened, then it will synthesize correctly.
The DisplayPort core uses "getProjectDevice" to select whether GTX or GTH is used in the design.
As a result, the script will always default to GTX when there is no project.
This issue will be fixed in the next release of the core.
As a work-around, use the Project flow when implementing the DisplayPort core targeting a GTH transceiver.
For a detailed list of Vivado LogiCORE IP DisplayPort Release Notes and Known Issues, see (Xilinx Answer 54522).
7/3/2013 - Initial release