I passed this in the window of the local Pandora shop and had to take a closer look because the wording just seemed so odd.
I think it might be ok, but it just sounds so...clunky.
"Become extinct" just flows better. Or even "Be extinct"
"Go" seems to indicate you could come back, and I'm pretty sure extinction is a one way street.
I just feel if you're going to spunk £55 on a rose gold bejewelled statement of hysterical BFFness you'd want it to be grammatically correct.
Disclaimer- I am the sort of person who tweets companies when they have spelling mistakes in their literature. 