Gameplay>lore in my eyes, limited class/race combos puts you in a situation where you may have to play a race you hate (i.e. BE's and Tauren) to play a class you like (Paladin).
Should just open it up.
"But my lore!", most people don't care, including blizzard half the time. They can't go 3 years without retconning themselves.
I'm sorry that I came off insulting earlier (bit grouchy, that's entirely on me). However, there isn't much lore-bending to night elf paladins the way Legion presented it (paladin martial training being applied to the existing Priestess of the Moon teachings/techniques); if anything the big thing would be trying to convince Blizzard to apply a white/silver color filter to their abilities (since the night elf paladins are directly channeling Elune, rather than the Light or a totemic medium for the Light like An'she or Rezan).
Right now, the only real red-flag combos, to me, are forsaken paladins and draenei warlocks, and that's more due to how the class affects the race in question (immolation and severe corruption, respectively). Most others can be justified through cultural cross-pollination, or one sect taking another's teachings and applying it to their own, which doesn't require a big lore twist so much as the factions' member races organically exchanging ideas, beliefs, and teachings the more they come in contact with one another.
Be seeing you guys on Bloodsail Buccaneers NA!
Are you that dense? Every paladin draws his strength from the light. Some call it the Light, some call it An'she, some call it Naaru, and some call it Elune. The result is all the same. Huntresses are de facto Night Elf Paladins. They just happen to be called by another name.