I’ve seen the same notification. Said I had to pass 3 levels by a certain time to qualify. I did and I received a second notification that I qualified. Beyond that, no idea what’s in store for us.
This event is only live for some days to celebrate with you all the 5 year Anniversary of Soda!
It will basically spread a total pot of 10 million Gold Bars (for real) amongst all of the players that manage to complete the rainbow to the Troll's Treasure.
You have until tomorrow to pass 3 levels and qualify (like @candysodacrusher has) and then you will enter a 2nd phase of the event that will begin soon.
This 2nd phase will begin on Friday. It will ask you to complete a Bubblegum Hill event and you will be sharing that 10 million gold bars with everyone else that beats the event as well.
Hope this made sense but feel free to ask more if you have any doubts!