Ultimately, this serves two purposes: not only would this prepare the next generation of OASIS user to utilize the resource better than the current and past generations did, it groomed them to potentially run it better than he did thanks to lessons from the past.
Putting it all together, the entire OASIS challenge in Ready Player One is meant to show Halliday’s regretful decisions in life, as well as impart his advice about running the OASIS.
With no heir and a lonely lifestyle that was a by-product of his sole ownership of the OASIS, Halliday had one last chance to leave his lasting legacy in the right hands.