Commodus had a brother named Geta whom he murdered and decreed a damnatio memoriae. In other words if anyone spoke this name out loud he would be killed summarily. The Goths appear right around this time… seems probable that perhaps Getae was not used anymore due to this and Goths became used.
The Getae were part of the Thracian super tribe which was the largest white tribe in the world according to Herodotus. Massagetae, Tyragetae, Thysagetae, were spread all over Eurasia and definitely did not disappear. Also the Goths couldn't have just appeared out of the mist. Not just Jordanes made the connection… the Goths were the Getae.
