I wouldn't say it's aimed at Britney herself, it's the song. Honestly, I can't say the song had a lot of longevity on me and it's just a cute little summer bop, but it's not bad.
They said the album they presented to their label last year "wasn't good enough", not Pretty Girls. They just said PG "wasn't right for them" and in an interview they said that Britney is "smashing it right now".