Question: Do the G5 ponies have cutie marks or not? Cause I've seen artwork, both official and fanmade, where they do and where they don't. But when they do they're always the same, so...?
According to synopsis I've read, there is currently no magic in the land, and they might be on a quest to bring it back. A lack of magic is probably the reason why they don't have cutie marks.
As for identical cutie marks... Could be place holders?
They only seem to have them on one side from what we've seen. I bet there might be an effort to bring them back, especially because Celestia, Rainbow Dash, Fluttershy and Twilight's cutie marks can be seen in the still we've got.