Why do some Xilinx Evaluation Kit schematics not line up with Xilinx design guidelines or interface user guides?
Xilinx Evaluation Kits are intended to be used by customers who wish to become familiar with Xilinx technology, prototype designs, and showcase particular features of the FPGA on the board. They can be used as a tool to get a customer designs kick started. However, Xilinx Evaluation Kits should not be used as a guide or copied when designing a customer board.
Xilinx Evaluation Kits can sometimes be designed and developed quite early in the lifecycle of the particular FPGA on the board, and therefore may be designed before all of the characterization are complete or the necessary requirements are documented in the Silicon User Guides. For that reason, Evaluation Kits should not be used as a template and should not be copied by customers for their own board development; they may not meet the requirements for particular features (such as MGT decoupling, MIG, etc.) as these might not have been fully characterized at the time.
In short, customers should always reference the appropriate user guide for the feature or interface they want to use rather than relying solely on the schematics of the Xilinx Evaluation Kits.