The question should be...Star 94 should be classified as modern AC? (Answer: YES)
I don't quite agree with you there. Yes, Star plays a lot of product that could be called modern AC: Linkin Park, One Republic, Finger 11, etc. But, Star plays a lot of stuff that would never make a modern AC playlist, such as Jordan Sparks, Colbie Caillat, Taylor Swift, etc. To me, Star is a CHR station that leaves out the young-leaning urban product. And that makes Star close to the CHR/Hot AC borderline, if there's such a thing.
I do agree with you that B98.5, with its latest playlist changes, is close to being a hot AC.
As far as stations deviating from whatever format they're supposed to be in, I don't think Atlanta is unique. Format labels mean only so much. For example, I've always felt there were two forms of hot AC, one like what B98.5 is doing and one that's really a modern AC (or pop conservative), such as what Charlotte's 107.9 The Link did before becoming basically a talk station. If you had to define The River's format, you'd probably say classic hits. But the new WCBS-FM in New York, which plays some '60s along with 70's and 80's and is much more CHRish, is also referred to as a classic hits station.
By the way, what is John McCain?