its likely Milan will invest to stay static, or maginal upgrades at best, but bear in mind Donna and Calhanoglu makes it risky for them. Roma are likely to cut. Atalanta probably not, their cost basis is pretty low. Juve will cut but I dont know if they'll have the money to replace. Napoli I'm not sure - I can see them being mostly static with a Koluilabiliy (spelling) sale but an okay-ish replacement.
So, I dont know where the investment pressure is? We'll need to invest to go further in the CL, but one of the big things from Conte is development of players, not a Mourinho-style-just-replace-them-all.