What would they flip to? Seattle is fairly well-served with all four or five dominant formats. CHR, Rhythmic, AC, Rock, Country. What else is there?
Each format you mention has multiple subsets.
CHR and Rhythmic CHR.
Urban and Urban AC
CHUrban
Modern or Contemporary country and 80-90's country gold
Hot AC, Ac, Soft AC, and even rhythmic AC like KTWV in LA
Classic hits and even Oldies
Rock has many divisions, from Active Rock, Alternative, Album rock and derivatives like Jack, which is sort of an AC Rock.
News and talk have various variants
Sports is a major biller.
Spanish language formats including adult hits, Regional Mexican, Reggaetón (Spanish Churban), tropical, AC and several others are viable.
Christian music has several viable varieties, and teaching & Preaching have many variants.
In many communities, there are formats in Farsi, both major Chinese dialects, Hindi, Tagalog, Vietnamese, Japanese, Korean and others with profitable service groups.
There are mostly non-comm alternatives like jazz and classical.
And there are derivatives and mixes.