That's called contextual targeting: " If iOS 14 users opt out, they will still be shown ads, but they’ll be based on other methods like contextual targeting rather than based on their IDFA. " https://clearcode.cc/blog/apple-idfa/#apple-skadnetwork

That works so poorly Facebook doesn't even bid on showing ads for those users currently: " And Facebook doesn’t even bid on iOS users that have Limit Ad Tracking (LAT) enabled " https://www.adexchanger.com/data-exchanges/what-do-apples-pr...