28And he said unto them, Ye know how that it is an unlawful thing for a man that is a Jew to keep company, or come unto one of another nation; but God hath shewed me that I should not call any man common or unclean. 29Therefore came I unto you without gainsaying, as soon as I was sent for: I ask therefore for what intent ye have sent for me?
It was about who Peter could associate with, and that's everyone. The change I was referring to, is that Paul identifies that which determines why we ought not
to be "partakers with them." It's no longer because Gentile or Jew. It's because of obedient vs not obedient to God. I think the warning has to do with the power of sin to influence those who are walking the path of cleanliness they were given as a gift, so as not to "return to the vomit" so to speak. The paradigm for partaking was changed. Before, it made no difference whether or obedient or not, Peter wouldn't partake with Gentiles simply because they were Gentiles, even if those Gentiles were obedient to God.