Does referral attribution still work post-iOS 14?

[Eshan Mathur]

I'm looking to understand the post-iOS 14 performance of referral attribution and finding the documentation unhelpful.

Some companies like AppsFlyer and Branch.io are saying iOS 14 does not affect referral attribution because it does not utilize IDFA. I'm wondering 1) if the same is true for Firebase. If so, 2) can anyone explain (on a detailed level) how user invite attribution works without IDFA across a deferred deep link, and why it works when things like ad campaign attribution doesn't?

Finally, 3) does anyone have recent, pre and post-iOS 14 success rates for referral attribution? We're trying to understand the level of attribution risk involved in using Firebase for this.