Each event has its own in-app boosters, which are different from the purchases in your regular TV stations because they are designed for the event mechanics. Since each event offers a different reward, each event will have its own purchases. This means, the event purchases are only valid in the current event. 

 

No-ads will work during the whole game in all your parks, including all events.

 

Please take in mind that your regular purchases will be working forever on all your permanent TV stations. The event is a voluntary challenge, and your regular progress won't be affected by your event results.