Kind of a late reply as I have been away from the forums for a while. At the time I made that post it was the correct info. Since then Blizz has stated that we wont be getting those vendors, instead they plan on making all the gear transmogable. They just gave no time frame as to when the change would be live.
PvP Item Transmogs
Rather than utilize the Replica PvP Vendors that were originally added in patch 4.3.0, we’re changing all of the original WoW Classic (Era) PvP gear to be usable as transmog appearances.
All of these pieces of armor have been and will continue to be available from the Legacy Armor and Legacy Weapon Quartermasters in both the Champion’s Hall in Stormwind and the Hall of Legends in Orgrimmar.