Well, but... did "My past is not today" even happen?

I mean... well it's just promotional clip(like perfect day for fun... which seems rather impossible to happened(there were no time in which this situation could take place)), and did Sunset do anything worth of becoming alicorn during it? No. To be honest we don't even know when it happened(if it happened)... after or before Rainbow Rocks(if before she rather should have wings after pony up)?

This is why I think that this song(well because of this song Sunsed intrigued me and i started watch it all) is announcement of Sunset becoming alicorn... but this happened not during the song but during friendship games. When she transform in Daydream Shimmer - this was the moment she really did something great.