I get exactly what you're saying and you're right.
Malone would've been back in the mid-70s. There were a few other guys in the 70s that went straight from high school or some weird JUCO situation to the draft, and then I'm pretty sure it didn't happen again until the mid 90s. I remember them bringing in the one and done rule at some point, but back in the 80s, guys just didn't declare early that much for whatever reason. If you go look at the hardship lists in the 80s, it's usually 10-15 mostly Juniors and an occasional Soph. Can't remember if it was a minimum age thing or what. Pretty sure Jordan, Barkley, Magic, Bird, Dominique etc all played 3 years in college.