I have spent this morning testing out one particular level of Spearmint Snowstorm after having played and taken screenshots of about a dozen of them.
So far I have not come to repeats and reached the second gold chest for the event.
What I know so far:
Most of these levels are impossible to pass without spending gold for extra moves, even for players on a top win streak plus super colour bombs enabled. Many of these levels require more than one UFO to pass on a first attempt. Some require a UFO plus a party popper to pass, or a UFO plus extra moves.
I think all players get the same sequence of these levels.