Is there sufficient lore in-game

[Sorelai-wyrmrest-accord (Sorelai)]

Try this:

Horde Roleplay: A Lore Guide for Beginners

This guide has been compiled by a number of individuals who have chosen Horde as their main faction. Please use this guide to fuel your own character ideas! Remember that roleplay lore is like a tool to write your own stories. It should feel inspirational, but never constraining. If you have an idea that goes beyond the general expectations for that race e.g. a blood elf druid or a half-dragon orc, just remember that authenticity comes from detail. The more background knowledge you have, and the…

I have found the three volumes of the Warcraft Chronicles to be a very concise overview of the lore. They cover about 20,000 years of history.