Could Musk successfully make the case that, despite this technically being public information, curating it in such a way to track him personally constitutes harassment?
I don't really see this flying in front of a court. This information is easily accessible publicly literally one search to get the aircraft registration number and a second one on Flightradar24 or any of the other sites/apps to see where it is. It's not "technically public" as onsite paper records at your mayor's office, it's widely accessible online public.
So if Elon's aircraft identifier was meant to be publicly accessible even though he is using that program, why does this privacy program exist in the first place?