IANAL but the pardon power (A) only extends to criminal punishments, not civil liabilities and (B) copyright lawsuits can be launched by anybody, not just the Department of Justice.

So, barring further Might Makes Right shit--which I'm not willing to fully rule out--Trump can't fully shield Zuckerberg et al.

They can also sue in France, or Spain, or Japan.

How unlikely it is for Trump to declare AI national security and simply make it lawless playground fro Zuck & Co.