The ability of the cargo version of the 747 to swing up the nose (that's why the cockpit is in the bulge on the top) will be missed. Cargo versions of currently produced airliners will not be capable of doing this.
Actually, if you look at the graph in the article, you will see that the 747 would have probably been cancelled around 2006 already if it weren't for the freighter variants. From 2006 to 2012 they only delivered freighters.
https://www.youtube.com/watch?v=1VZO8Lt78Go