As a new player you also get a free do-over once, so if you arrive at your first event and decide you would rather be playing a slightly different race after the fact, that's absolutely accommodated. I've not seen it happen before, but I imagine they just sort of hand-wave it as a retcon so that you don't lose your limited roleplaying progress from only having 1 event under your belt (having to spend your second event reintroducing yourself, rejoining guilds, etc. would be pretty stale).