I'm not so sure this study proves anything new, too. We always knew some Goths came from Scandinavia, that they mixed extensively with less mobile people in the regions they passed through during the age of migration, and that Gothic identity was (at least eventually) more tied to Arianism than to ancestry, so that when they became Catholic they stopped identifying as Gothic.

The real wild Gothic origin story is that the island of Gotland got overpopulated and they decided by lottery which 1/3 of them should leave.