Rob Delaney was a walk-on who turned out to be a good player, so you never know. For that matter, Bucknell guards Charles Lee, Kevin Bettencourt, and Abe Badmus were non-scholarship players who did pretty well. Badmus might be the best example since he committed in the spring after his senior year. Guys like Brian Ehlers and Pat Campolieta were also great non-scholarship players.
Agree that he’s a long shot though. As for being a “preferred” walk-on, iin many cases it means the coaching staff has identified something about the player that might give them a chance to be productive down the road. Maybe a big man who is just starting to find his coordination or a great pure shooter who needs to develop his game or a solid PG who can’t shoot. Etc. I know Bucknell last winter/spring looked at a number of non-scholarship big men for a preferred walk-on spot. They landed one but we likely won’t know for two years whether he will ever contribute. Another one they looked at was Billy Murphy, who ended up as a walk-on at LC.