There are active blood elf guilds. In the past month or so, I’ve ran into:
- Division 23 (exclusively blood elves with a military flavour)
- Crimson Vanguard (exclusively blood knights and very heavy on the military discipline)
- Sanguine Eye (exclusively blood elf, bit on the xenophobic and supremacist side)
- House Mournflame (exclusively blood elf noble house, didn’t interact too much)
- Sin Serrar (exclusively blood elves, balancing military and supremacy elements)
I’ve got positive experiences with all of them. There might be more, but I’ve been playing an orc and a tauren so I’ve not been over-exposed to the blood elf community.
There are also several active Horde guilds that will accept blood elves but offer a more multicultural environment. If you are looking for casual hub-based RP that you can enjoy every night, then that’s the only reason why I would choose to move away from the Horde and to the Alliance.
Highvale are an excellent choice but as they’ve already been advertised, two alternatives that I have run into include House Dawnshrine and the Legacy of Nalore, who also fit the criteria you’re asking for.