No spoilers will be marked! Proceed with caution!
Karnak was motivated partially by wanting to literally save Ocean's soul.
Perhaps he knew a little more than he lets on about "what comes next," and knew that of all the kids, Ocean is the one who wouldn't be going anywhere good (or at least, knew that if there was a chance any of the kids wouldn't get to Heaven, it would be her). However, he also knew that if he gave her a chance to do the right thing, in the end, she would. So, the competition was set up the way it was at least partially for her to properly redeem herself.After returning to her life, Jane/Penny will reach out to Mischa's girlfriend Talia.
Whether she remembers her experiences in limbo, or simply finds out in the aftermath of the accident that one of her classmates had a serious girlfriend, she'll get into contact with Talia to let her know what happened, so she gets closure and knows Mischa didn't abandon her....Honestly, I choose to believe this to make me slightly less sad about Mischa's whole deal.
Ride The Cyclone takes place in the same universe as The Good Place
It’s Ocean’s test to get in. It’s why she has to make the big choice at the end. The others are actors. Her real choir mates are having their own test. Constance didn't remember riding the Cyclone until her monologue.
Throughout the show Constance acts like she did in life — shy, put-upon by Ocean, and ashamed of Uranium and being the Nicest Girl in Town. But according to her monologue, she finally appreciated her life and her town as she was plummeting to her death. By all accounts, then, she should have been in a better mental space throughout the show, unless... she was experiencing some minor Ghost Amnesia up until the monologue, when Karnak pushed her to talk about the lead-up to the Cyclone incident, which triggered her memory. It may even be that getting everything off her chest, having it witnessed by the others and by Karnak, is what allowed the memory to be unlocked.Jane/Penny never rode the Cyclone.
We know she was found near the wreckage, missing her head, but it's never said she was on the ride itself. She also didn't get her fortune read with the other kids, and is absent during "The Uranium Suite", which shows the choir boarding the ride. It's possible Penny was at the fair with the rest of the school, but wasn't in the choir and was off doing her own thing... only to be in the exact wrong spot at the exact wrong moment, being killed when the coaster fell apart and plummeted to the ground. Having part of a steel coaster fall onto you from several feet in the air could certainly decapitate you.