Generally, you are on the mark in being skeptical about a massive adjustment. About the only thing Classic Hits programmers are doing right now is culling out the songs from 1980-81 that are dropping in popularity.
There are really only about 50 titles in those two years that are still getting heavy airplay, and about half of those are by Pat Benatar, Blondie, Journey, Hall & Oates, Tom Petty, Foreigner, The Police and REO Speedwagon. But there are some lesser titles in there by artists like Billy Joel, Bruce Springsteen, and even Michael Jackson that are likely to be casualties by the 2024-26 time frame you identified. By that time, we'll undoubtedly be looking at 1982, given that CHR's resurgence began in 1983.