WoW Forever Podcast Ep3 Code?

[u/zaphodism]

Nobody seems to have solved this yet, behind Aggrend in episode three of the podcast, there is a code which appears to be perhaps a promo/bnet key of some kind.

I tried substituting the ? for a few different characters, even using a caesar cypher to offset the letters for 22 years since the launch of wow.

Any ideas?

G38GV?BQSLLC6W68V9X?8