If it doesn't stop at the 33rd switch, it's almost definitely correct to pull the lever no matter where you are in the order, if it comes to your turn. The chance that 8 billion people will all choose not to pull the lever is almost zero - That also includes children and babies who have no concept of morality, and one of them may even pull it accidentally. Over a long enough timeline, this would almost definitely happen. In fact, depending on how far apart the levers were, the trolly reaching new levers might not even outpace the rate of children being born, so it would just be an unending string of babies and levers after a certain point.

If you accept that it will eventually be pulled, then if you are in the first 32 people, you're killing fewer people by pulling it, because eventually, all but 1 person will die otherwise. If you're past the 32nd person, eventually everyone except 1 person will die, so it really just comes down to whether or not you want to be the last human alive. Since most people value their own life more than the life of an unknown stranger, the correct choice is to pull the lever.