The Holy Grail was mentioned at the very beginning of the third season in Sailor Moon (1992). It was what the Death Busters, Sailor Neptune and Sailor Uranus were trying to obtain in the first half of the season by collecting the three talismans from pure hearts.
Chibiusa never mentioned the Holy Grail to the Sailor Senshi, or that it was used as a weapon in the original series.
Sailor Uranus uses Space Sword Blaster in this episode, a move that she does not use in the original series until Evil Mirror Under a Curse! Mamoru in a Nightmare Trap (1996). However, she did use the attack in Sailor Moon SuperS: The Movie: Black Dream Hole (1995).
Setsuna was never mentioned to be a student in Sailor Moon (1992), nor did she meet Reika. She first appeared when Haruka and Michiru were revealed to possess two of the talismans, and when she used the third and final talisman, the Garnet Orb, to call upon the Holy Grail.
Sailor Neptune never used her violin skills in conjunction with sea-related attacks in the original anime series.