Remnant of Corruption NPCs Visible without Unfinished Headpiece

Description:
The Remnant of Corruption (ID 22438) NPCs surrounding Gul'dan in Shadowmoon Valley are visible before equipping the Unfinished Headpiece (ID 31360).

• http://www.wowhead.com/npc=22094/remnant-of-hate
• http://www.wowhead.com/npc=22437/remnant-of-malice
• http://www.wowhead.com/npc=22438/remnant-of-greed
• http://www.wowhead.com/npc=22439/remnant-of-corruption
• http://www.wowhead.com/npc=22440/remnant-of-pride

None of them are supposed to be visible until you equip the headpiece.

• http://www.wowhead.com/item=31360/unfinished-headpiece

And Gul'dan should be kneeling unless you're initiating an event like summoning Cyrukh the Firelord.

• http://www.wowhead.com/npc=21181/cyrukh-the-firelord

Video: https://gfycat.com/PointlessQuickDikdik

Branch(es): 3.3.5

TC rev. hash/commit:
TrinityCore rev. e478434146fd 2017-04-09 19:18:22 -0300 (3.3.5 branch) (Win64, Release, Static)

TDB version: 335.62

Operating system: Windows 10 Server & Client

Reproduce the issue on the 3.3.5 branch using NPCs 22094, 22437, 22438, 22439, and 22440, item 31360, and the linked video as reference. Trace how their visibility and Gul'dan's kneeling state are controlled around the Cyrukh event. Done means the Remnants stay hidden until the headpiece is equipped and Gul'dan kneels when no event is being initiated.