I don’t see much posted yet in regards to the night elf scene, so in regards to kaldorei roleplay: night elves have a habit of flocking to wherever the next big thing is. That’s Ashenvale currently, because of the Ashenvale Autumn initiative, and will probably shift to Feralas when the Monsoon War server campaign starts. Amirdrassil generally isn’t that popular due to phasing issues.
I’m generally not a very big fan of server discords due to the nature of them, but the Amirdrassil discord is also a good shot at finding night elf roleplay. There’s a channel there that’s used to announce night elf-themed events and a channel to spark more casual roleplay in. Also plugging Acrona’s night elf roleplay thread, because it has a neat oversight of guilds, events and discords.