In my personal opinion, that would be both a stretch of this recital and an abusive use of the GDPR. You don’t control what ads are shown to anyone because they are served by a third party, and you have a good faith belief that you are not subject to GDPR under Recital 23. My guess is that if you used an ad network that specialized in EU ads, you’d be subject to it. But using code from a US ad network that may have some EU advertisers now or in the future shouldn’t expose you.

But I don’t disagree that some EU countries that intend to abuse the GDPR for the purpose of generating massive amounts of revenue from fines may try to make this kind of claim. One of the problems with GDPR is that when you combine unclear regulation with the lack of moral hazard that government agencies enjoy and the financial incentive of massive fines, you create a monster that will constantly seek to expand who and what is covered under it.