Quest : Horde Presence. Flag can't be placed (quest itself works).

I see whats going on here and will have a fix in the next day or two 😁

This is a problem across most of the cores. 
Here is what we know.   

• The banner was never a requirement to complete the quest. (an over sight on official?)
• The item should be removed when used. I dont believe it was ever removed at turn in. (Again maybe players should use the item as part of the quest and it is assumed they should) .
  This opens up the quesion, should we add our own check at quest turn in and remove the item? I say leave it, and allow the player to delete at their own discretion.
• The message  "Required Talon Den", is the only real fix that is needed to make it as the offical servers (at one point in time) had it.

Hehe, Blizz seems were planning to make a dungeon or whatever with this place 😃
Seems like that. This quest, The Den quest, Elites, Named Elites inside, Named Rare Elites  

I suppose because of that vanilla have such "rudiments" and u can encounter them from time to time.

So, I suppose next statements are true/should be done such way:

1) Yes, the banner was never a requirement to complete the quest. (Seems like it's official). So it's like a toy (maybe it was planned to do something else but it never was implemented).
2) I think it is right way to leave the banner in player's inventory (and some database comments says that it is true but I'm not sure). What if somebody would like to return in this weird place that is far from horde's flight nodes and place this thing again as a proclamation of war?  

(P.S.: btw aside this quest there are others in vanilla that leaves some quest-related stuff in players inventory (maybe part of them is mangos minor "bugs" but I suppose most of them are official) such as letters, runes or so. Can't give you any detailed info but from time to time scanning inventory I can't remember what is this thing and what it is doing in my inv? Then google says that it is a part of a quest that I've done 10-15 lvls ago) 😃 

So, why not to leave this flag inside inventory too? At least it is a usable "toy".

This would be blizzlike, I think

here is the fix for mangos Zero, one and two.

ZERO: REL21_16_041
ONE: REL21_12_028
TWO: REL21_11_056