I don't know if this question is relevant or not.
The Agnelli/Elkann family have plenty of money, with diversifed assets in nearly every type of business model imaginable. Their fortune is sustainable due to this versatility. They are not putting all of their eggs in one financial basket.
I think a question that should be asked is if Calciopoli never happened, would Juve even have/had the need for a foreign investor?
Now THAT poses a very interesting question, as to how their business model with the club would have been affected. It's very easy to say that the status quo in regards to how they were doing business back then, but take a look at Inter and Milan for example. 2 clubs who were not nearly as affected, if at all, from Calciopoli, and look at their current state.
Would Juve have actually gone forward with owning their own Stadium? Would the business model have changed in order to compensate for dwindling revenue?
All interesting scenarios, in my opinion.