Welcome to the forum.
Collection event shards do not reset the pack counter for the guaranteed shards at 500 pack opened.
I hope this answers your question.
Community Admin@xlreightx Hey there. Coincidentally I happened to have an account that didn't unlock the collection event yet, and which had unused shards sitting on it.
My collection event also showed the checkmark, so I guess it's faulty logic there and the checkmark just looks for the existence of unspent shards on your account. Minor bug but an understandable point of confusion.
Anyway, I went ahead and completed the event and I was correctly granted the shards, so you should be safe to do so. If you are going to complete the event, be sure to do so while it's live, delaying and opening the packs later can lead to issues.
The only possible problem I foresee is in the edge case of you having all Heirlooms/Mythics already. The logic as of the last shard-granting event was that you should only be able to stack enough shards to buy all of the current Mythics, and one more. I assume that this is updated to "all current Mythics +2", but I haven't seen it myself and don't want to present my assumption as a fact, especially when there's money involved.
So if you don't already have all Mythic items, there should be no problem.
If you do have them all, you can go for it but please let us know how it goes. If you get stacked up to 300 shards, great. If it somehow doesn't work, we'll look into it.
I'm not 100% sure but I think it relies on if you purchased the collection event for the second anniversary, I have an account that I purchased the whole collection event for the second anniversary collection event that gave me the shards, I currently don't have shards on my account but it is showing the checkmark Ashwell. I don't know if this clears anything up but it should grant you the shards either way.
