This is something I've talked about for years. Not only in the case of WMMO, but there's CMG's "Eagle" both in Jacksonville and Tampa that like WMMO and other 'Classic Hits" stations across the country, don't play artists such as Michael Jackson and Madonna and the pop hits. How can you call yourself classic hits excluding the king and queen of the 80s decade? IMO, true classic hits formats are Retro Top 40 offering multiple genres of music, not just rock.
Apparently, there is leeway in the format that it can be a popular version of classic rock as well as a variety-based and pop-oriented one. I always believed there should be a designation applied. There's Soft AC, Rhythmic AC, Hot AC, and AC to show format specificity. There's Top 40M and Top 40R. There's country designations. You get the point.
The playlist difference between Orlando's WMMO and WOCL (105.9 Sunny FM) is enormous yet both are designated as classic hits. I've been making the case for a classic hits station to come to Jacksonville for many years. Usually, a poster will say they already have one. I then explain for the umpteenth time why that's just a specialized version and not the real thing.