On an HD Radio, there’s a readout for the format but it has to fit into a narrow list. For instance, both Z100 and The Buzz are described as “Top 40”. K103 has always been described as “Soft Rock” but they’re now shown as “Adult Hits”, the same as Charlie.
Probably more a sign of the times than anything else. Music considered AC today would’ve been considered Hot AC 10-15 years ago. Music considered Hot AC today would’ve been considered Adult Top 40 10-15 years ago. AC stations across the country generally are not “soft rock” anymore, and hardly anyone uses that branding anymore. Maybe it’s an attempt to go after the younger demographics.