Never heard the such. You mean that you bought a new home that has not had the finish coat applied to the interior? I am not being rude or offensive, but I have heard so many things, this one is just amazing.
Primer in the old days did not exist, it used to be flat paint. Flat paint is used all the time on walls but more and more you see semi gloss, because you can clean it and it makes the room look bigger because of light reflection, but I will sit at Dodgeman's campfire on this one also, paint that wall now and you should charge the labor and material to the builder. It was his/her job anyway.
Sorry, sometimes I get so wrapped up in foolishness that some builders are passing out.