They emailed me back again, this is what they said
"Only new players take part in testing.
You can start a new game (for example, in a different browser with new game data) to test new features before introducing them to all players."

So you can make a new account if you want to play the event, but it means starting over...
We already knew that, but at least it's confirmed... They dont care about those that spent money on their current account.