Made a new alt, this Troll Rogue. I decided I wanted to get a jump on Silvermoon reputation by running all the way to Eversong Woods and doing the quests in the Blood Elf starting area, Sunstrider Isle. I did this before with Orc Warrior in WoW Classic. I walked from Durotar all the way to Mulgore because I wanted get an early jump on Thunder Bluff reputation.
Originally, doing the level 1-4 quests in Sunstrider Isle was possible in Vanilla TBC, no matter what race you chose. You had to run all the way there, but you could get an early jump on Silvermoon rep. The only quest that was inaccessible was the one regarding the Blood Elf racial where you practice Mana Tap on a few of the Mana Worms. However, every Sunstrider Isle quest was all unavailable to my Troll. I was only able to start questing at the Ruins of Silvermoon at level 4.
I want to bring an alt to the Draenei starting area to see if this also affects Alliance. I started SW quests on my Gnome because I wanted Exalted with SW for a Horse and not that noisy chicken. If I wanted rep for an elephant, I’d expect to be able to do all the Draenei quests as well.
In the Dranei starting area the quests are worded as if you are a survivor of the exodar crash and wouldnt make sense narratively as another race so it may be a similar thing for the belf starting quests.
This is false. The only race-specific quest made unavailable is that Mana Tap one. For Draenei it was the quest that requires you to use Gift of the Naaru.
This was a feature of OG TBC. You could ask a Mage for teleport to Exodar, run a level 1 alt to Azuremyst Isle, and start questing there and gaining Exodar rep as early as level 1.