i'm pretty sure this is only the 2nd time it has happened, first time being tropical rouge precure op having the original singers while the cures are in background, but we did get a precure version of the op
1. 1:26 You can immediately hear that this is gluing 2. 2:23 Yuki's Voice actor??? 3. Usually all Pretty Cure endings end on a good note, but this ending ended on a sad note, as if it were a typical night in the first half of 2010 and the end is morning
Also the end of this song reminded me of Credits from the 80's cartoon series where they also played cheerful music at first, and sad music at the end, and they sang "See you tomorrow" (for example Noddy's Toyland Adventures)