While Battle for Azeroth requires a fast HDD with at least 70 GB of free space, the upcoming expansion of Blizzard's World of Warcraft — Shadowlands — apparently needs an SSD with 100 GB of free space or more. The eight major installment in the World of Warcraft series is expected to arrive at the end of October on all continents.
https://www.notebookcheck.net/Blizzard-You-will-need-an-SSD-to-play-World-of-Warcraft-Shadowlands.490876.0.html