A goblin working for Blizzard sent me a mail encouraging me to exchange my gold for WoW tokens and play again. Seeing how little use I made of previous offers of 7 free days and the Battle for Azeroth beta test, I don't think I will. Even if the gold will become effectively useless once the expansion comes out, because you can't buy expansions with gold. Which makes me wonder whether my gold will be good when Blizzard finally releases their vanilla WoW nostalgia servers, or whether those need an expansion pack as well to play.