Maybe its because i'm originally from Philly, but I thought Penn's reputation for having strong linkages to many post-bac programs was pretty well known.
Goucher (one of four post-bac programs that link with Penn) sent 7 students to Penn last year directly via their linkage, with an additional 1-2 getting in from the post-bac via applying normally (
source). This alone represents over 5% of their entering class.
JHU's post-bac program sent 33 students to Penn over the last 5 years, so about 7 a year, the same as Goucher. This accounts for another 5% of their entering class, bringing it to 10% just from those two programs (
source). Both are traditional post bac programs in the same way SDN uses the term.
The other two post-bac programs they link with are Bryn Mawr and their own post-bac program, and I can't imagine both don't send students there in similar numbers. For what its worth, everything I wrote in my original post was mentioned multiple times to me, so its probably just complete random luck that we ended up having very different experiences.