My personal decision in this regard now is that people who don't play an active role in my day-to-day, regular activities, and who show little or no interest in my personal life - either family or old friends - probably aren't interested in my parties (or my funeral either), and don't deserve an invite.
I think this advice of Madam Quixote's is a very good rule of thumb. That they don't get in touch to impart family business to you anymore would indicate that they are going for the full on shun so they would be highly unlikely to come anyway. go with gut instinct though like others have said.
Happy Silver Wedding Anniversary!