Why and how are the Goths able to deflect the Huns?
Depending on that answer, the question of Slavic migration is to be viewed consequently.
If, for example, the Goths are able to install themselves long-term as overlords both of the Bosporan Greeks and of various still fully nomadic groups, and integrate both long-term as auxiliaries into their kingdom's military forces (e.g. a Bosporan Gothic navy and Alano-Gothic horseback bowmen), then I'm sure they're also able to allot a place to the slash-and-burn agriculturalists of the Northern forests which the Slavs were, exacting tribute from them for "protection", recruiting mercenaries and/or a white water fleet (rowmen) from among them? (Is that realistic by this time already?)
If the Goths merely deflect the Huns by sheer luck with OTL's political structures, then they're going to fall to the next wave (Avars?). That would already have changed enough, for example stabilising the Roman Empire in a critical moment, so that Roman policies regarding the Pontic steppe could be more proactive again in the 5th century.