What is the functional difference between 'deleted' and 'archived but not available for anyone to view' or is there one?
The Obama administration sites were moved to the National Archives and Trump started over with new sites. That's exactly the same thing that happened when Bush II and Clinton left office (Clinton was the first to have a web site, so we don't have any precedent before that). Nothing has been "deleted".
Oddly, no one seemed to screech when Obama "deleted" all the material from the Bush II administration. Why not?