Kaplan was not the reason Alt 92.3 failed. The first few months under Michael Martin's leadershup were misguided musically and presentation-wise.
You can arguably blame KROQ on him, but how much of it was him being made to be the scapegoat for decisions above him (ie letting go of Kevin, Allie & Jensen and how it was done) depends on who you ask. Prior to this run at Audacy, every Alternative station he ran over-performed.
Kaplan developed the two-minute promise during his first run at Entercom at 107.7 The End where it helped grow the ratings immensely.
He's not making a morning show change. He was the one who brought the Woody Show to KYSR Los Angeles and built it into something iHeart could syndicate nationally. He and Woody worked together at Nassau Broadcasting in New Jersey in the early/mid-90s.
Under John Allers, WRFF succeeded because "Radio 104.5" continued the tradition in the market set by WPLY of having a Pop Alternative lean making it more female or office friendly than most Alternative stations in the country. When he was let go and it was rebranded as "Alt 104.5", it was put more in line with the rest of the company's stations in the format. Kaplan has done both variations of the format during his career and the company obviously sees that WRFF needs a stronger leader by bringing him in, so watching the music and imaging will be the key to whether he's being given enough control to make the station more sellable again.