Just that whatever the technological threshold for being included in the sanctions is, every Xilinx chip is complex/advanced/high-performance enough that it would definitely meet it. In other words, unlike with TI chips, you can tell just from the brand name that Russia is definitely not supposed to have it.

Practically speaking, an FPGA could be acting as anything from an encrypted transceiver to a flight controller to an AI coprocessor. Regardless, though, it’d be a relatively complex unit of functionality – one of the more important chips in the drone, and therefore one of the more important to deny to Russia.