>...I am sorta doubtful companies will deliberately make less efficient appliances if it goes away.

Working in the manufacturing space, I have no doubt designs will change and energy consumption will go up. They will be able to remove sensors, heat water hotter in dishwashers and clothes washers, run cycles more aggressively, and use cheaper motors (such as HVAC fans). Any item you can remove from the bill of materials adds to the profit directly.

Capital expenditure versus operating expenditure is a common tradeoff discussed in a business sense, and the Energy Star gave a pretty darn good comparison for opex for consumers. Taking that away (even with some of the games that have been played over the years) is a huge loss for consumers.