A statement from Blizzard explains: “The authentic launch of WOW Classic Gold WoW Classic became made to re-create the difficulty and assignment of patch 1.12 from the unique World of Warcraft launch.
"While we strived to deliver a loyal re-introduction of that release, many raid encounters turned out to be easier than the primary time round—players without a doubt have been extra skilled and organized, and patch updates substantially expanded participant energy.
“These modifications presently encompass (however aren't confined to): World buffs (like Rallying Cry of the Dragonslayer and others) disabled in Raid times, Restoring mechanics that were eliminated early on to some Raid bosses, No boss debuff restriction (up from 16 debuffs in mmobc.com WoW Classic), and Increased health on bosses, to offset participant buffs and the removed debuff restrict.”