Well yes, Turalyon definitely can be that for the Alliance. I wish Blizzard could find some way to show current players a bit more of WC2 Turalyon. I was mostly talking about early WoW there. Thrall was not good Horde representation (Cairne was a much better choice) since he really was between the two worlds. And Varian definitely was not good Alliance representation and the same character on the Horde side would have fit so much better.
I do think they could reinvent Thrall into a proper Horde leader. They did not retire him when they could so he is still around, he is the most iconic Horde leader, he got his mom to give him a pep talk from the afterlife and he was originally a shaman and we are heading into an Elemental-focused expansion. They absolutely can bring Thrall late in this expac and give him a new hero moment to redefine him and make him cool again.