I just came back to WoW from a hiatus that started back in Cataclysm. I started back up a week after BfA dropped, I am exalted with The Honorbound and The Nightfallen. IMHO the nightfallen rep grind didnt take too long, felt just right to be honest. I am going for Highmountain next, if it is similar to Nightfallen I will not be upset in the slightest.
Nightfallen Rep is Mostly Gained through the Suramar Story Quests. Highmountain is literally a much longer and much more Irksome Grind and Literally takes Twice as Long as Pre Buff Void Elves and Pre Buff Lightforged Draenei. the big reason they buffed the 2 Argus Factions is More Allies whined about how it takes 2-3 Weeks to unlock Void Elves when it takes about 6 Weeks to unlock highmountain tauren. Alliance literally has the 2 Easiest Legion Allied Races to unlock which are only getting easier. but highmountain gets no love because it is a leveling zone and highmountain takes twice as long. this is especially true because greater highmountain insignias are gated behind 2 levels of RNG that a greater Argussian Reach insignia is not.
Literally everyone has a life outside of an MMO, even if you did every WQ every day that's an average of 750 rep/day, which means it would take at least a consecutive month to get from Revered to Exalted (21k rep) , and that's not counting honored to revered which is another 2-3 weeks (12k rep). AND unlike Suramar (high honored/revered) or Highmountain (honored at least), completing the Argus storyline leaves you in friendly, MAYBE low honored if you had some sort of rep buff.Bottom line: Horde got the preferential treatment, as usual.
As someone who has already done these reps, long ago... I'm glad that my friends won't have to spend so long doing them. ^_^