Inside Serpentshrine Cavern, Victory! isn’t removed.
Inside Tempest Keep, Pyroblast Cinnamon Ball isn’t removed.
The Victory! buff gives a bonus to various stats and is obtained in either Goldshire, Elwynn Forest for Alliance players or Brill, Tirisfal Glades for Horde players. When anyone completes the quest Stop the Fires!, everyone in the town will receive the 1 hour buff. As for the Hallow’s End candies (Soothing Spearmint Candy, Pyroblast Cinnamon Ball, G.N.E.R.D.S., and Chewy Fel Taffy), each are obtained from Handful of Candy, which requires the player to speak to a nearby Candy Bucket.
Currently, entering a raid instance and pulling enemies inside of a raid instance do not wipe these buffs obtained from the Hallow’s End event. It is unknown if this will apply to Invocation of the Wickerman or not, which should be obtainable later today. While not really impactful, a bonus to reputation is quite nice for alts. In Burning Crusade Classic, Blizzard has had a very strong stance against world buffs, making it a surprise that the Hallow’s End event buffs and consumables are working inside raids.