What does it mean when it say not verified as genuine AirPods???

This is very, very briefly discussed in this document If you get a 'Cannot Verify AirPods' alert - Apple Support

Apple has some way to determine if Airpods are genuine or counterfeit.

"You can choose to not connect your unverified AirPods, or to connect them in Bluetooth settings. If you connect your unverified AirPods, they may not behave as expected."

It then offers a link that helps you verify if they are genuine but frankly I cannot see how just identify a model does that.