I cannot find this on amazon or aliexpress but @daniel added this last month. No install instructions in the commit message so I assume that means standard flashing procedure with no hoops to jump through? Can you comment @daniel
The Adtran is - as far as I know - only available for american organisations like larger living communities and universitys etc (if you know more - please correct me here)
If you can find one at ebay it will most probably be too expensive anyway.
One option is to get a 1-card computer like raspberry pi/nanopi with a M.2 key E slot and get a MT7925 or Qualcomm WCN7850 M.2 card.
But the best option is the Banana Pi R4 with its Wifi7 card - even though its not "polished" just yet, most things are already working
And its actually cheap considering what you get if you compare it to other Wifi7 routers.