Abbreviating that is so misleading, it's incredibly hard to not see it as bad faith! MNPI means "material non-public information". You're saying "non-public information is fine but material non-public information is not", without making it as obvious.
Yes, it has to be material. "Owes $30b in taxes" is ABSOLUTELY material. If on top of that you learn about it from IRS insider contacts, enjoy your time in prison.
Please do read the Wikipedia article; it has a section on the US. https://en.wikipedia.org/wiki/Insider_trading
> SEC regulation FD ("Fair Disclosure") requires that if a company intentionally discloses material non-public information to one person, it must simultaneously disclose that information to the public at large.