Avowed will be available on Battle.net, which means you can buy it for about 1.4M gold in WoW if you want to

It's time to start gold farming in World of Warcraft because Avowed is coming to the Battle.net launcher when it releases next year. You can pre-order Obsidian's big fantasy RPG on Blizzard's store right now, including the premium edition that includes five days of early access to the game.

That means that, with some effort, you could acquire Avowed by farming gold in WoW. According to this site that tracks the price of WoW Tokens, a game time voucher WoW players can buy for in-game gold and convert to $15 of Blizzard bucks...