well, they can be remembered as:
. those who managed to earn their marks at the same time.
. those that have the same brand.
. the ones that helped the other ponies discover their talents.
. Sweetie Belle would be remembered as a great singer (or songwriter) Apple Bloom would be remembered as a great carpenter, Scootaloo would be remembered as a great athlete.
But anyway, only time can tell us, only the future of the G5 can tell us if: Apple Bloom, Sweetie Belle and Scootaloo also achieved a place in history.