No - only applies to public companies.
If there is active litigation, then despoliation of evidence may become an issue. But I don't think there was any active litigation at the time.
My own take (from having read pretty much everything on the topic, including new Seth Wickersham book), is that the Patriots, including Brady and Kraft, weren't certain what Jastremski may or may not have done in the bathroom. We know that Brady liked the balls on the low side, and so it is quite plausible Jastremski routinely let out a bit of pressure before games. They still might well have been within regulation pressure before the ideal gas law did its thing though.
I've been surprised there hasn't been more leaking from the NFL offices - usually once people leave they are happy to screw their old bosses.