User blog comment:DerpyDoodle/Wolf/@comment-25129545-20140920201145/@comment-10733804-20140925005041

Wolf's removal most likely was because of a few reasons
 * The Star Fox series was represented by essentially the same character 3 times so it was a waste of space in the roster.
 * Wolf wasn't exactly anything special in Brawl. He did not have a huge fanbase, a great moveset or anything memorable about him so Sakurai knew removing him wouldn't impact the fanbase much (which is true since many people barely noticed him gone when the roster was revealed).
 * If you look at any predicted list of removed characters in SSB4 from before the roster was shown you will notice that Wolf is pretty much on every list.
 * Even though Falco is more similar to Fox than Wolf it seemed like there was a higher chance of Wolf's removal because he was a hard to unlock character that only appeared in Brawl while Falco was an easy to unlock character in both Melee and Brawl. Falco is far more iconic as both a Star Fox character and SSB character than Wolf.