The number of players in MLB who went to college is increasing. The NCAA put out a list of where the players in the playoffs attended college.
World Series 2019: Here’s where the Houston Astros and Washington Nationals played college baseball
I think fairly soon, there will be only a few minor leagues as we know them, most of the training will be collegiate baseball. The Big Leagues will make much more profit than running minor leagues.
I am in the process of reading the book “Astroball” by Ben Reiter and one of the things I found most interesting was that Jeff Luhnow and his team created a database to track Division II and Division III players while they were working for the Cardinals. There was no one-stop shop, so to speak, for that information previously. Professional teams are copycats, so it’s not surprising to see so many D2 and D3 players listed on that link, but I doubt you would have seen many in the postseason 10 years ago.