Britney released Radar, which really is a Blackout track, not a Circus track.

It was just added in as a bonus because she knew she wanted to release it. (I always share favorites with the artists, lmao.)
Anyway, Starstruck is on TFM Deluxe, and really, I look at TFM as a re-release of The Fame, it just has more songs than Rihanna's re-release. So I can't see why not, it works perfectly. Flo Rida's new music comes out soon, so it would be perfect timing.