[Jaccmcmcnn]

Does that go for every country?

It's Impossible to speak for each and every region.

And also a warranty claim would only be used when the product is damaged, dont work anymore etc right or do I understand this incorrectly?

You're absolutely correct.

As said, It may not come to this, but there's a chance that It can.

so it would be best not to sell them?

I mean, it depends on the method that you used. If you used something like DNA, where the airpods could be in anyones hands, I believe it should be safe to sell them as long as you don't use your real name when selling them.