[2019] Prestige Snowdown Master Yi on PBE

I was rerolling some skin shards on PBE and I got a Prestige Snowdown Master Yi skin.

It was a blank image without a name and it was an epic skin.

When looking at the purchase history I saw this:

https://i.redd.it/ps51ddiq1au31.png

It didn't give me a skin, but I got it multiple times.

https://i.redd.it/tqgz17pb2au31.png

I don't think this will be an actual skin since snow man yi exists. But it's still strange why this is possible to get on PBE.