I don't see Zandalar trolls spectacular at all. I'd have prefered blood trolls as a playable allied subrace for the Horde.
However, it looks like we can only fight them doing dungeons and quests.
These forum restrictions are absurd btw.
Check out that link:
media.mmo-champion.com / images / news / 2017 / november / NewArtOfWoW034.jpg