One of Blizzard's narrative designers has released the following tweet:
"It's not that all blood elf eyes have changed from green to gold. It's that the potential for golden eyes is present, based in part on the individual's degree of devotion to the Light."
This makes the whole question as to whose eyes might change from green to gold a lot more clear cut.
- It is due to devotion to the Light that Blood Elven eyes may change to gold over time.
- The degree of an elf’s eye colour change is dependent upon their devotion to the Light.
- Elves who have no faith in, or mastery over the Light will not be gaining golden eyes.
- Those most dedicated to the Light and its wielding will be first to attain golden eyes. Others may see their eye colour lighten, or make the change to gold over time.
As in-game NPCs as Lor'themar and Valeera continue to have green eyes in BfA, while only Blood Knight NPCs and Liadrin are featuring golden eyes, we will stick to the explanation offered in the tweet above.
Edit: A small update based on another tweet of the narrative designer:
"For players, we intentionally didn't restrict which classes can have golden eyes. Whatever story you want to make for your character's eye color, more power to you.
For NPCs, we will be selective. Priests & paladins are more likely to have them, but others can if it makes sense."
