I feel that this strategy made sense in the era of physical media, but nowadays it's completely absurd... In Britney's case, they released exclusive UK tracks for the 25th anniversary of Oops! I Did It Again, they recently released Scary for Halloween, and it's only a matter of time before they release exclusive tracks from Circus at some special moment, but I think everything is easier when the songs belong to the same record label as the artist, in this case Sony Music. In Kesha's case, from what was said above, the song belongs to Universal Music, and there was certainly some kind of dispute between the two that prevented the release. I doubt they wouldn't have been able to release it if there had been effort. This narrative that Dirty Picture will be exclusive to vinyl and digital purchases definitely came at the last minute; otherwise, they wouldn't have made the song available on streaming services just to keep it blocked. What a mess... At least we're left with some information.