Well, I wouldn't give up on the car. It is not the car. I have had the XC40 for almost 5 months now and I love it to death. I have driven it at speeds of over 100 and no vibration. If you don't have that much mileage, just return it and get another XC 40, yes, I would cite lemon law.
This is just a thought... is there a possibility that the pilot assist is causing this? Can you try high speed with pilot assist off? I have noticed with pilot assist, if you forcefully / purposely drove the car over the lines, it will cause a rumble on the steering wheel. It is as off the car is protesting. If you let go of the steering wheel altogether it will tug the wheel/car back into the lane. So my thinking, if there is something wrong with the pilot assist cameras/software, is it possible that it is "rumbling" the steering wheel?