The 1 million gold restriction seems to have been removed from Retail WoW character transfers. Players are now be able to transfer characters with more than 1 million gold.
Gold Restriction Removed from Character Transfers
Originally posted by @GirlGoblin1 on Twitter and linked to us by Panthea, the 1 million gold restriction on character transfers seems to have been removed on the Blizzard Support article on Character Transfers.