Normally it's plenty. At that time of the morning there used to be long lines at security and customs; I haven't been through there since AZ de-hubbed MXP, but I'd guess the loss of AZ flights has shortened the lines.

Flights from the US tend to arrive 15 to 40 minutes early- there is a lot of padding built in the schedules. I wouldn't be concerned about a connection longer than 50 minutes.

(I've made 25 minute connections on the outbound, domestic to int'l, and checked luggage made it too. I've made inbound connections under 1 hour, but my bags were on the next flight).