So… I’m starting up in Wow since the MoP Remix event seemed interesting (and is).
I’ve been roleplaying in other games left and right and I was curious to find if AD had the same kind of Discord communities that tend to exist elsewhere, only to find dead links.
Which communties tend to be active lately? Outside of guilds (for now at least)
Hello! I know of one larger Discord that also has a collection of various smaller, more niche communities gathered in a channel. Might be your best bet. 
Since you’re RPing a Night Elf Mage(I assume?) there is also the Amirdrassil Discord!
No idea how to link it tho, lmao!
There is also the Wardens Discord!
Hi!
The link Sarvaad posted is a good start, and if you’re interesting in night elf themed roleplay, you may also find a few communities listed here:
There are discord communities covering certain areas as well. I know that Gilneas, Stromgarde and Stormwind have their own discord. And Duskwood as well, I suspect.