I would say that it would cause all of the other campaigns to laser-focus on the black vote, but I doubt it even would have mattered. Biden would have truly been the inevitable nominee he always was going to be. That fact was just delayed due to South Carolina going fourth.
Butterfly effect I'd say SC going first would potentially help Sanders due to the fact that Biden would do better in IA, NH and NV Sanders could outright win Iowa while winning New Hampshire by a bigger margin since some of Pete's votes in this scenario would likely go to Biden although Sanders probably only narrowly wins Nevada. Super Tuesday possibly instead of it being the Biden comeback could be the story of if Sanders can keep his momentum going after winning 3 states in a row leading into Super Tuesday but who knows Biden after winning the first state may just sweep 49/50 in the primary.
See, I think this would be the case. Even before Biden's three early state losing streak, I think a lot of Democrats did want reassurance that he could win, and beating a more crowded field significantly in South Carolina may still have delivered on that. Sanders would likely still stay in until Super Tuesday at least though regardless of what happened, I do agree with that.