The trial keys and the ominous keys are not next to each other on the creative inventory.

The ominous key is the last item on the item section of the creative inventory while the trial key is placed between the book related items.

Paper, books, books and quills and enchanted books are all next to each other on the inventory. When the trial key was added, it was placed in between them, which is a little bit weird once you pay attention to it.