The MLB has been under scrutiny for its treatment of Minor League Baseball players. The current system is not sustainable. Minor League players are treated as disposable due to the low wages and lack of benefits.
In an effort to address these issues, the MLB is considering a new plan that would establish a "minor league" system with four tiers: AAA, AA, A-Advanced and A-Short Season. The four tiers would be designed in such a way that players could move between them based on their performance and development. Also you can read this article: https://www.golf.dk/sponsoreret/vil-der-vaere-en-minor-league-baseball-i-2022