Kevin points out a tweet from Adam Schefter that does remind us all that the players and their teams can't communicate yet. So that would seem to make this report by Pro Football Talk that the Green Bay Packers told their players to report on Saturday unlikely. But Jason Wilde confirmed the rumor with his own sources, and the Packers aren't the only team with such rumors.
The Packers have been good and received specific exemptions for player events, one for the Tailgate Tour and another for the ring ceremony, and GM Ted Thompson has been known to have been playing by the rules. Only Bucs head coach Raheem Morris admitted he has contact with his players, but there are permitted avenues of contact through team doctors and player representatives at the labor meetings. And they've been keeping all the players informed so word has certainly gotten around.
I'm not normally comfortable with an unsourced post, but this seems to be likely.