That would be hilarious. A terrible admin for NASA, but hilarious.
Edit: Although come to think of it, when he started out, Bridenstine was a climate change... not "denier", but was skeptical that the cause is anthropogenic. But to his credit, he changed his opinion when presented with new data, and turned out to be a pretty good NASA admin.
Who knows, maybe a flat-earther would surprise us! The timeline we're in is already so strange...