I don't think so, because this was postd by a dev.
The reason for the 15 minute timer was that the spiders he's referring to in Delving Into Darkness were dropping 4 gold per kill, 100%. So, peeps would sneak over, loot, start over, sneak, loot, ad infinitum. Devs put a 15 minute timer on the zone, IF you killed the spiders, to stop that exploit while they tried to fix the coding. (It's been fixed).
And for the OP... If you think THAT xp is good, go play in Splitpaw, I recommened Harclave's free xp while you afk
