I doubt it. Brands which provide free breakfast to all are likely to be more favorted by "summer vacationers" traveling with their families (that's a subset of leisure travelers) than those FS properties that charge high amounts per person for breakfast and nickel-and-dime for everything.

And, indeed, I tend to see proportionally way more families with kids when I stay at Fairfields than when I stay at FS Marriott (non-suites) or even Courtyards. Similarly, I see way more families with kids when staying at Hampton Inns than when staying at FS Hilton or even HGI.

There are other things that traveling families like, including everyone in the same suite, so whether the breakfast is free or not, brands like Mariott Suites and Embassy Suites also get lots of families with kids in my experience.