In the ancient history of Azeroth, Roy had used his frost demon blood and the viruses contained in his blood to create the extremely terrifying Galakrond, the Father of Dragons, thereby triggering the subsequent dragon war. This was the true mark Roy had left in history under the influence of the spacetime flux.
It was because of completing this historical event by a freak combination of factors that Roy and his group suddenly triggered a time jump and disappeared from the timeline again.
As for the two Old Gods who had been waiting eagerly to use Roy to save them in this historical node, they were destined to be disappointed. Roy directly abandoned them, resulting in Yogg-Saron and N'Zoth gnashing their teeth and cursing at him for a long time in their whispers. Especially N'Zoth, when he bewitched the Black Aspect, Neltharion, he mentioned the name 'Osiris' more than once in his endless whispers…
The Old Gods had written Roy's name down in their notebooks…