They look like the equivalent of Rivnuts, a threaded rivet that accepts a bolt.
Generally you don’t want to strip out factory finished floor, walls, or ceiling unless they are unsalvageable. Doing so will cost you extra time & money, for no extra benefit.
It is also debatable whether those are actually holding the paneling on. Normally they use clips that make the panels easily removable. Push on, pull off type.
Cheers!
"Wherever I may roam, I always take my home." ~ Van_Dweller