I think they might be doing something similar to a suggestion from earlier in the year.
Command Decision
Basically, if you were Venice and took over most of Italy, rather than wait for a mean time to happen, you could just immediately declare yourself the Kingdom of Italy, or even earlier with all the problems that might bring you.
You would gain cores, but everyone might gain up on you.
Additionally, read his suggestion about the HRE. You could declare an imperial embargo or some such without waiting for random events.
I am guessing Missions will be more like, form Italy, than ruling the HRE.