That type of transfer was a TBC thing not Era/Vanilla.
Last thing I recall seeing about allowing that sort of movement from PVE to PVP is in the thread below but that is for TBC only. Apologies to those that were affected by that dark day on August 9.
Continuing the discussion from Burning Crusade Classic Realm Consolidation August 9:
In Era? Was that an unpublished change?
I moved this character off of Bloodsail maybe a month or so ago and the free transfer offered was only Mankrik. I didn’t need to attempt a paid transfer so I’d not seen that was now allowed.