WoW tokens are a simple market. All tokens are the same and have a static actual currency cost. When there are more people who want to buy gold than people who want to sell gold, the price drops. When there is more When more people want to sell gold than buy it, the price goes up.
As the gold price of $ 20 tokens falls, more gold holders are willing to convert them into tokens, and fewer rich people are willing to buy gold at this rate. As the price of gold rises, the value of tokens begins to exceed the time value of some market participants accumulating gold, and they stop selling gold. At the same time, other people with cash are also attracted to the market because they can get a lot of gold from the tokens.
Regardless, the market will eventually reach equilibrium, at which point demand and supply are comparable.
Allowing WoW tokens for Battle.net balance will generate new demand for tokens. In World of Warcraft, there are some players who have a lot of gold, and they still have a lot of surpluses even after paying the subscription fee with tokens. The number of subscriptions that any player can use is limited, and the amount of these tokens will not affect the gold reserves held by some players. Now, suppose these players want to buy something in other Blizzard games, they have the incentive to buy more tokens.
This indicates that this change will lead to a permanent increase in the price of the token. But how many of these people? How much Battle.net balance do they need? How many people will be tempted to spend money on gold? These are big issues, each of which will affect the economics of these games.
Players of other Blizzard games may see some changes, but not so drastic in nature. Hearthstone, Overwatch, and Heroes of the Storm all have in-game currencies and economies, but these currencies are only used to purchase items from Blizzard; there is no transaction between players.
In the warm-up and vigil games, players may only see more fancy makeup skins in the game. In Hearthstone, giving a bunch of players a new way to buy cards may lead to seeing more complete decks on lower levels of the ladder, but many “meta” decks are already cheap.