Searching "giga-goose" before June 3rd brings up basically nothing, someone last year called this species a "gigantic goose" and a bunch of unrelated things. I wonder where the nickname came from, and how important it was towards getting this article published.
Also I wonder if there's a move away from "mega" towards "giga" as mega anything seems kinda small. I can't see "tera" ever being a thing, I can't think of an independent connection to some other word meaning large.
Etymologically, “giga” does make more sense as a generic ’big’ prefix than “mega”. I believe that the former basically means “great” while the latter means “mighty”, which is less flexible.
“Tera” has the problem of being overloaded. It’s a homophone with “terra” which is a common prefix for things related to the Earth or ground. Also that lack of a strong second consonant hurts it. Etymologically it means “monstrous”, which is even less flexible.
Also I wonder if there's a move away from "mega" towards "giga" as mega anything seems kinda small. I can't see "tera" ever being a thing, I can't think of an independent connection to some other word meaning large.