"If you use the more common sense of major as a race important in the greater scheme of things, and not just important to itself, then the Aslan are certainly a major race."
Obviously Grandfather didn't subscribe to the Vilani way of thinking when he made coynes. All that travel and experimentation seem to impress on him what sophonts in the original Ancients space would become important.
Note that Grandfather changed the coyns several times....See CT AM Droyne, p. 45.
Or Adv 12 SotA, P 32.