Yes, "used to". Now, in 2024, the same supreme court has decided that presidents have immunity in all official acts, from stealing documents, up to and including assassination attempts on their opponents. This is a radical shift in how the court operates.
This "opponent assassination" hypothetical gets bandied about a lot but I have not seen any evidence that any court considers that to be an "official act". Official acts are constrained to legitimate exercises of constitutional authority and are not merely anything a President (or especially, an ex-President) does.
the only thing radical is the opinions of people you are listening to if you believe SCOTUS enabled legally sanctioned assassinations. It was political hyperbole based on nothing, and it worked (with you). Think for yourself.
And generally courts/judges just choose the scope of their legal opinions based on how far reaching they want the legal principles to apply.
IMHO, copyright-ability of APIs is so far away from their political agenda that they probably just decided to leave the issue on a cliffhanger...