Yes, it gets the same glowing tip all primal weapons get before their upgrade. If you look at all the old primal weapons, they all get that plus an additional form which features more of their element.

As for the live letter, yes I remember that but at the same time, it really is a system that makes no sense for their naming methods. Also by that logic, we should be getting a lot of new primal "hard" and "extreme" modes that were only 1 shots.

If we want to call the final form extreme, then why not keep it simple like "Leviathan" without hard attached anywhere then "Leviathan Extreme" ?

When you call it "Leviathan Hard", you imply there is a mode below hard when in fact there isn't.
And by that logic, how is Ravana Hard and Bismark Hard explained? They are story mode fights pre-60.