Reading the study they cite (https://urj.uccs.edu/index.php/urj/article/view/266), it's not that the replacements have an agenda, it's that replacing a few lyrics doesn't really cover up the original intent of a song, and a lot of the songs they cover have non-kid-friendly themes. Another major complaint is the music videos tend to feature kids having fun by dancing around a big house with fancy clothes and expensive stuff, which romanticizes wealth and promotes consumerism. Lyrics romanticizing wealth like "can't you taste this gold" tend not to be censored.
The basic idea is that playing the Kidz Bop version of a Flo Rida song for your kid is similar to showing them the airplane-censored version of Pulp Fiction. If they're too young for the real thing, they're probably too young for the censored version.
Not really. The research seems to be relatively novel, not a watered down version of a different study being repeated by children as your comment would suggest. My point was that the research just wasn't overly prestigious.
The basic idea is that playing the Kidz Bop version of a Flo Rida song for your kid is similar to showing them the airplane-censored version of Pulp Fiction. If they're too young for the real thing, they're probably too young for the censored version.