Players used to be able to buy Gold directly from the in-game store. In the current version of the game, Gold can be acquired only from the Wheel, from Scratchers and as rewards in several other places. Match to Win decided to focus on other methods of rewarding players with Gold than relying only on in-app purchases. Boosts and goodies can still be earned by play, the Wheel and other methods.
If you had purchased Gold, you can still use it, just like you did before. Item prices didn't change, either. And as always, the game is completely free to play and win real cash -- that won't ever change!