Every new kingdom will have a World Progression event after a certain time.
When entering the building, the event results are still visible.
When moving to an older castle using the Novice Transfer you can get the benefit from that server. therefor it is highly advisable to move to an older kingdom to get these rewards.
For example if you make a new account and transfer it to Kingdom 1 or 2 before you reach Castle level 5, you can claim all the rewards they reached in 2019-06 when they had their World Progression event.