MiLB is now:
Complex Leagues (Arizona [ACL] and FL [FCL] which used to be Rookie Ball), Low A, High A, AA and AAA. You still see players, college players in particular, skipping level. With increased metrics I also think there is more tolerance to move players through faster or at paces tailored to their development AND the needs of the team. Letting them get a taste even if they aren't immediately success (and some spectacular examples where they are successful. I'm thinking Michael Harris III). CJ Abrams is another HS draftee with less than 500 MiLB ABs before playing in the majors.
In the next couple of classes you will have players who might have otherwise been drafted out of HS (If I'm not mistaken, this year we have those who were subjected to the 5 round draft and who really didn't have a senior year to show what they were capable of). Will be interesting to follow their trajectories.