One thing that Chad Stahelski’s John Wick did remarkably well was create a world that exists inside another that feels rich with history and lore, even if not all of it is explained.
The original Highlander, likely for budget reasons, never really made much of a dive into the world.
There were only a few immortal characters, and the movie gave no explanation as to how or why they all existed.
If he can do the same with Highlander, while creating the unique action scenes that he wants to, we could have a quite fantastic film on our hands.