I'm gonna start of with saying I am not 100% sure it is a bug, but it did seem weird. When I opened the Wild Hunt crate I got two copies of the collectible Wild Hunt Leaf-Dance Aura. In addition to that I got a bonus reward (the purple Rootbrim Hat with flower). It doesn't really impact stuff since I already owned the dance memento from the first time the crates were available (and thus both dupes turned into gems correctly), it just feels strange that the crates are able to offer two copies of a reward that you can only have 1 of per account.