Yes, pre-trial publicity is usually only considered in change of venue cases. I remember in the Juan Corona trials back in the 70s, pre-trial publicity was brought up after the initial trial and they did get a new trial based partly on that... result was the same.
IMHO, instead of pre-trial publicity, Chauvin might have had a chance with SCOTUS on the angle of BLM’ers threatening violence to jurors and the city if they gave the “wrong” verdict.