UPDATE PROTECTION is a service we provide for individual trainers that you can purchase for a small fee that enables you to get new updated versions of paid trainers totally FREE or in other words it 'protects' you from having to buy updated trainers again and again as game updates.
For example, If UPDATE PROTECTION is NOT purchased, in case the game updates and new trainer is released, you will have to re-purchase the new trainer. On the other hand, people who bought update protection will get all the new trainers totally FREE of charge.
Please note that purchasing UPDATE PROTECTION does NOT mean that a trainer will be updated or you entitled to getting a new trainer released. It merely enables you to get updated trainers for free once they are released by the author.