Advertising companies and politicians like to play with semantics for the purpose of changing images. Big soda companies seem to be heavily invested in changing their images this year - with Pepsi completely revamping their packaging and Coke teaming up witt Jay-Z to promote Coke Zero - so it isn't entirely shocking to hear that they no longer want soda to be thought of as "carbonated soft drinks." Instead, they're "sparkling beverages."
In what some might describe as a blending of advertising and politics, the name change represents some social climbing on the part of soda companies. They are trying to distance themselves from their high-calorie, junk food roots, which politicians and other people in positions of power continually hold against them. Unfortunately for the cola companies, soda is so popular that no matter what Coke and Pepsi executives decide to call it, changing the name for the product to "sparkling beverage" is like trying to change the word for "beer": it's just not going to happen.