If you are in line by the time the park closes (regular hours or HHN) they'll let you ride/experience the attraction. Don't worry they won't kick you out. Do note that if a ride is very very new they might close the line earlier than park closing to guarantee the ride closes for work on time.

When Universal Studios reaches its official closing time, the "eviction" process is actually quite gradual and guest-friendly rather than an immediate sweep. At the stroke of closing, the entrances to all attraction queues are closed; however, if you are already standing in line for a ride, you are almost always permitted to stay and ride, even if the wait extends an hour past closing. Once you exit an attraction, security and "Team Members" will gently guide you toward the front of the park by blocking off paths to the back sections. Retail stores on the main thoroughfares, such as the Universal Studios Store, often stay open for 30 to 60 minutes past the official closing time to allow for "last-minute" souvenir shopping. In 2026, the CityWalk areas outside the gates remain vibrant and open much later than the parks, so while you cannot re-enter the themed lands, the transition from the park to the exit is designed to be a slow stroll rather than a forced march, allowing guests to take final photos in a relatively empty park.