You don't know one way or the other. What we do know for sure Obama spoke with them when there were active cases on the Supreme Court docket against Obama.
By that definition, the Supreme Court Justices could never have any conversations, meetings or attend any Presidential functions EVER. You see, during each session of the Court there can be as many as a dozen cases (or more) pending on the Court's docket that would feature President as either the Planfiff or the Defendant.