Well, what the website actually says is that the 96th is "one only 3 or 4 entire Army Division awarded the Presidential Unit Citation for heroic action during World War II", not in the entire history of the award. The page is badly formatted, and the part about just WWII is wrapped around on the next line and it is hard to follow.
According to your information the 96th is the fourth army division to receive an Army PUC for WII (aside from the fact that the 101st received two).
How does one locate a copy of the General Order? Since I made the first post, a copy of some official looking document has been scanned and posted on the same website as before. Is this the general order?