For one, Joe Paterno is a high-profile individual, and the family has valid privacy concerns. There is some aspect where the family may suffer harm from the public knowing the extent of his estate. There was a great deal of disclosure on the part of Paterno's wife in terms of his salary and severance packages, and terms of his entire estate.

In the case of Paterno, all the parties to the will agreed to the terms, and there was no dispute or controversy over the terms of the will. The court considered the harm that could come to the family by leaving the will open to public record.

However, for instance, if Joe left all his estate to the Humane Society and his surviving children fought his will, it would not have been sealed. (this is an extreme example, but there are people out there who leave their entire estates to charity to the shock and outrage of their descendants). If there was a controversy, the will would remain public record at least during the court proceedings.

It's possible to do, but it rarely ever happens, and when it does it's only reserved for high profile and high wealth individuals. Also, there cannot be any controversy surrounding the will, and all heirs and descendants need to be in agreement to the will's terms.

So, the average Joe won't get their will sealed. there has to be a reason.

Hope this helps. If you're concerned about your privacy when you pass on, consider having an estate lawyer draw you up a living trust, which will help you avoid court filings and probate after you pass away.

Thanks!