This would just be a very minor convenience/efficiency thing for people who like to go for multiple unique build challenges in a row.
Reasoning: The game itself also sorts perks alphabetically. If Nightlight did the same, then after you put one build together in the same order, play it and then proceed to do the next one, you could be able to do so more quickly, since each perk of the new build now has a higher chance of being on the same page as the previous perk in the same slot, or close to it.