He can do it. He has the skill set.
You can make yourself a better athlete, with regard to acceleration/jumping with better / proper training. I've learned a lot about that over the past years.
Hex-bar deadlifting is the key, going really heavy. There is a great podcast a few years ago by Tim Ferris interviewing a well known Nike/ former USA Track & Field coach that names hex bar deadling is the #1 (as of now) way to improve acceleration. It's what they do with guys trying to win the 100/200 meter sprints. This trainer works with super stars trying out for the NFL combine / in the NFL, through Nike.
Separatley, I also know someone personally that was offered a 100% free ride to a tip-top lax program (which is rare for men's lacrosse, a full scholarship). Essentially he's a top 10 player in the country in highschool; partly because he's such a superior athlete. He just hex-bar dead-lifted for years, and now he is just way faster than everyone else. The kid, when you look at his parents, doesn't have superior genes. They are just normal people. He just worked his legs into being supperior. He has ridiculous ups / acceleration now.
Champ can do the same thing. Does he have time to do it before this NBA draft? Probalby not - but he can work himself into better acceleration / jumping, etc, and get improvements over time.