Treasure Goblins is the generic term they use in the Game Guide…
https://us.diablo3.com/en-us/game/guide/gameplay/world#-treasure-goblins
The buff is for all goblin types except the insufferable miscreants, not just the treasure goblin type.
All of these types are doubled…
Treasure Goblin
Gem Hoarder
Gilded Baron
Blood Thief
Odious Collector
Malevolent Tormentor
Insufferable Miscreant
Gelatinous Sire
Rainbow Goblin
Menagerist Goblin
