There is a list of Xilinx eval boards with FMC slots that are officially supported. The Kintex Ultrascale is not one of them. I believe that to be because it is new, and no one (ADI, Xilinx, or Avnet) has had the opportunity to verify.
1) Is it the intent of ADI that the Kintex Ultrascale (EK-U1-KCU105 with FMC slot) support the FMC (AD-FMCADC3-EBZ)?
2) Does ADI or Xilinx know of any reason that the FMC will not work on the Ultrascale board?
3) Is there an IP port necessary that sits on the Xilinx Kintex-7 eval board to migrate to the Ultrascale board?
4) If so, does ADI plan to make the port and if so, is there a known schedule?
5) Are source and all IP cores available so that we can make the port if the answer to 2 is no, that is the boards should work together?