The first tieflings you meet as Drow do attack you unless you pass an intimidation check, there should be something similar for the burning tavern though.
But there is a reason why the tieflings and druids at the grove are not hostile, you introduce yourself to them by helping them defend their base.
The last part is definitely a valid point. The current map is somewhat sparsely populated, so there's a limited amount of NPCs you can run into. In fact most of the NPCs on the map are of goblins, many of which will assume you're on their side because you're a drow. This is already a good example of racial reactivity done well in my opinion.
If the story takes us to more populated areas later on in the game I think there are going to be a lot more opportunities for NPCs to react to you based on your race.
