Meanwhile, LaCroix is just sparkling water and natural flavors (which is what I expect flavored seltzer/sparkling water to be). So that explains all that.
It also looks like the Kroger stuff is labeled as sparkling water beverage, just like the Target product I mentioned above, so I guess “sprakling water beverage” is the term for these (usually artificially?) sweetened, clear, fruit-flavored beverages. Or basically what we’d normally just call diet soda.