Can fleas jump on people after cats repel insects?

No, after the cat is repelled by insects, fleas will gradually leave the cat's body, because they can no longer get food from the cat. Fleas usually spread by jumping instead of climbing directly to another host. So fleas don't automatically jump on people after cats repel insects. However, if there are flea eggs or larvae in the environment (such as carpets and beds at home), they may continue to hatch and find new hosts while adults leave the cat.