The final verdict is in for this pet. Several sources, some of which include WoW GMs, have stated in no uncertain terms that the new blue and purple Essence of Competition pet (not to be confused with the red and gold Spirit of Competition) will NOT be released on EU and US servers. The NPCs on those servers who allow you to redeem the code are, in fact, a bug.
This pet has been auto-excluded from the collections of most members of the community. Additionally, I'm going to continue prohibiting people from adding this pet to their collections until the end of the event. For now, it's too easy for people to confuse this pet with the Spirit and then accidentally add it to their collections. This in turn triggers tons of people spamming them with messages to find out the secret of how they got it, when in truth, they don't have it at all. The few of you in China and other Asian regions who have actually collected this pet will be able to add it to your collections on August 25th, when the event is over.