Heads up: The @PlayApex Anniversary Collection Event heirloom pack had a bug.
It unintentionally reset the "counter" that guarantees you get heirloom shards every 500 packs. Only people who opened the heirloom pack before 3pm PT on 2/10 were affected, as the bug was fixed.
We're working on a hotfix to restore affected players' "bad luck protection" counters to their proper count (including additional packs opened since the bug).
If the bug prevented you from getting rewarded on your 500th pack, you'll receive a pack containing heirloom shards.
We're also going to grant affected players 5 Apex Packs for their trouble. We'll update when the fix has rolled out and we've confirmed that it's working properly.