Have you ever heard of the 20 cord loads of logs that turn into 17-18? I've never heard of anybody getting more firewood out of a measured load of logs.
If the logs are crooked, yes. Plus the seller "claims" there are "x" number of cords in his load. If reasonably straight, no. A cord of bucked rounds will ALWAYS stack up to over a cord after splitting. If you have doubts, read the 'what is a cord' gthread in the stickies up top. Do a few of the experiments yourself if that is what it takes to convince you.
Harry K