In order to review a goal, a coach just needed to have a timeout in hand. Challenge the goal and and be wrong, say goodbye to your timeout. That was it. If the proposed tweak to rule passes this offseason, being wrong will cost more than a timeout.
Now, don't get too excited. This still needs to be approved by the NHL Competition Committee and the Board of Governors. As a fan, I hope this passes and is in effect for next season.