Anyone can say what they want, meanwhile Milan AC won.
In my opinion it was a good match and also a good boost of self-esteem for the team.
They needed it after the last few games ended very badly, i understand good their mood very well: when someone works hard and doesnt get results they get depressed.
Milan has always had a very good potential and they have everything to be much higher in the table, maybe the reason was precisely Fonseca, and the team needed a coach who believes in the team more and can motivate the players for each game. I see this in Conte, when he comes to a new team he is filled with energy and inspires the players with this, you can see it when you watch his matches, maybe Conceicao is just such a coach, and yes, this victory is very important for Milan.
Appointing a coach to handle a club that is in decline is not an easy thing, we can see how Napoli performed last season and when they appointed Antonio Conte Napoli's performance improved again and currently Napoli looks very ambitious to be able to get the Scudetto as well as what happened to AC Milan this season where this club has declined since they fired Stefano Pioli and was replaced by Paulo Fonseca and after they fired this coach and was replaced by Sérgio Conceição Milan's performance improved slightly and was able to beat Inter Milan, this is a good change for Milan and it seems they were not wrong in making the decision to fire Fonseca.