as another non-native speaker, i think that while the person you're answering to didn't use the default way of expressing this in the english-speaking world, i did understand what they meant, i think they do know what opting means and i think the reasoning is this: when they say data collection is "opt in" by default they mean that by choosing to use a product, you are opting into your data being collected (at the same time). on the other hand, native speakers saying something is "opt out" describes the options or toggles one has available in the default case - when something is toggled "true", you (only) have the choice to toggle it of. so english speakers talk about the controls one has to CHANGE the status quo.

As another non-native speaker, I misunderstood what the person meant.