Tbc pre patch v soon

If by soon you mean at an unspecified point between now and the end of time - then yes it is!

If you mean soon like imminent then I feel you may be slightly wrong.

https://eu.forums.blizzard.com/en/wow/t/wow-classic-character-transfer-temporary-

I would suspect this will all be before the pre-patch lands.

I may be wrong!