Btw learned a thing about U23 teams in Serie C. It's not as simple as register the team there.
You need to actually get the spot for your team first. Milan got their spot for the coming season because Ascoli lost theirs due to financial issues.
Then another aspect is the group division. Rules are, for now, that only one U23 team can be in one group. Serie C is divided to 3 groups, geographically. North, middle, south. There are 3 U23 teams there now with Juve, Atalanta and Milan. Division was random this year and Atalanta got the best result by getting to the group A (north). Milan got to B and Juve got the shittiest draw with group C and some insane travelling.
They probably change the rules when more U23 teams enter the league. Because even if they don't care about kids traveling all those kilometers or Juve having to pay the traveling costs to Southern Italy, the teams in group C are financially fucked when they need to travel to Juve away game this season, those clubs there in South are particularly poor.