I would definitely wait until they include it, or look at options from Yamaha, Marantz or Denon. He wants HDMI 2.1 because it provides new features including Variable Refresh Rate, Auto Low Latency Mode, which is great for FPS (First Person Shooters), and 4K passthrough at 120 frames per second. These are huge benefits for the gaming and VR crowd.
At least when I bought my AV8802 back in the day, they did the HDMI 2.0 upgrade board for free. Did not think the upgrade would cost that much.