According to the news, AC Milan received a warning to add 1 Italian player to the squad, which this player can be selected if he is an alumni of the Milan academy, as well as Italian players who are alumni of other club's academies in Italy. If AC Milan fails to meet these requirements, then AC Milan will get a sanction of reducing the number of players from the initial 25 (total) to 24 players. I think, this is not a big problem for AC Milan, because they have their own academy, which may be find new talented players to promoted to the main squad list next season.
AC Milan is obliged to comply with Serie A regulations and avoid sanctions. because with the departure of Alessio Romagnoli and Mirante,
AC Milan did not meet the quota of players. But as far as I know AC Milan can always meet the regulations every season, so AC Milan can
definitely overcome the lack of player quota by registering players from their own academy. As you said AC Milan is a big Italian team that
has their own academy, which has a number of good players ready to be promoted to the first team. So far AC Milan has registered 7 Italian
players, so it only requires 1 more player to complete the quota. And that's a problem that AC Milan will soon solve, because AC Milan certainly
does not want to be penalized.