Not at all!
Reposting for visibility (other non free Xfer realm clusters include the NA PvE West & OCE PvP):
The 13 PvP East realms are made up of 2 separate clusters of 5 and 8 realms:
I play Horde with my guildies in the 5 realm cluster on the PvP East (Incendius and its 4 sister realms).