The bulk update request #2877 is pending approval.

create alias pile_of_gold (75) -> gold_pile (0)
create implication gold_pile (0) -> gold_(metal) (27338)

Reason: Dragons like gold. Their treasures usually comes in piles of gold coins, bars and jewelry.
The gold (object) form is more usual in the website.

Doesn't sound like sufficient justification to me, but to note: there's more tags as *_pile vs tags of pile_of_*.