You are right, he is the last one left, and I suspect Arnold Ziffel was long ago invited to someone’s dinner, not as the guest of honor, but as the main course.
A few years ago, I saw a program about "Urban Legends" involving movies and TV shows. There was an urban legend that Arnold was eaten at a farewell barbecue that was held for the cast when the series wrapped. Not true. (Arnold was played by a number of pigs during the series' run.)