Nope,cheap nasty mdf is standard on many Cabanon and later Conways. My Fiesta seems to have beds made from old crates that have been stored outside for a couple of years.
Last year, I fitted peg board on our camper. Having removed the original thin ply I welded some more support bars in place. I then varnished the peg board before undercoating and painting with a high quality wood paint to ensure it was waterproof. We no longer have condensation problems and the beds were cool to sleep on when in Narbonne in August last year.