I was never really clear on the details, 3 years or 4 years, but to me a junior player going back into the draft is not the same as a college player becoming a free agent.
There's a big difference in the situations of Stoll and J Schultz (or Bigos and Moffie).
Well junior players can be free agents too if they're old enough.
I know it's confusing, but at the root it's a very different situation than the Schultz/Wheeler one and much closer to the Stoll one, even if they're free agents rather than being redrafted.
There are other differences as well - when you draft a player in junior, you keep his rights for 2 years, for college players you keep his rights longer. College players cannot sign any deal without losing their NCAA eligibility, junior players can attend camp/get 9 game tryouts and still be sent back to junior. In other words, in several respects junior players have more rights under the CBA than college players, in one respect they have less
It's a compromise, not a loophole, that's why it's still in the CBA.