We had lots of rivalries back in Vanilla. They were starting to brew in Classic but the release of cross realm BG’s killed all server community. At least in Vanilla with server only BG’s, the rivalries extended into battlegrounds, which made it WAY more fun than queing into randoms on cross realm.
Cross realm has killed all server immersion, servers are now pointless.
I recall the occasional PVE/PVP trash talking between Deathwing and Kel’Thuzard way back when, because those were the only two PVP servers in the Mountain timezone … but it wasn’t anything consistent.
LOL, yeah, whenever someone asks about a good server and RP-PvP is indicated, the Deviate Delight folk come swarming in bashing Grobbulus. The Grobb Mob is more chill, and are more likely to recommend trying both and deciding which you like.
If there are, I’d expect it to be things like private server players against streamers, or the like. Somewhere that large amounts of the population have some identity they think is relevant.
There is, obviously, the anti-Heartseeker crowd - all the Horde-heavy PvP realms whose targets took the free transfers.
I played on Frostwolf throughout original WoW, and it was my experience that we really didn’t have a rivalry with any other realms until the Ahn’Qiraj War Effort got underway.
Then suddenly we were all over websites that were tracking each realm, and people from other realms were in our realm forum taunting us, and so on.
There are not even rivalries between Alliance and Horde players on our own server; because we never even see each other. X-realm BGs were the very beginning if what we now now as BFA.