Last year Penn State did not meet their deadline for a very small number of applicants and they came out with a new deadline - unlike this year where they haven’t given a deadline. This year, they have not met it for far more I believe because of the common app and EA. They should have hired many more people to work admissions if they already knew from last year that the number of applicants was high, and likely to go much higher with the inclusion of EA and Common App.
Re: Supplemental housing - This happens USUALLY if students accept last minute. January, February and even March usually does not get put into supplemental. I’ve known kids in supplemental that were upset and ended up loving it and not leaving when a double room became available. Especially if others in the room DO take the doubles - leaves an extra big room for a small number of kids. Some kids hate supplemental as well. For every example of one, you will find an example of another so it’s kind of a moot point. Regardless, February commits usually do not get supplemental. Even this year, because even after all of this mess - the number of students who attend will be near the same because they cannot accommodate more.