Hey! I'm new here, but saw that you were in mild-applicant-panic and wanted to assuage it as much as possible. The Purdue acceptance is mine, and I am currently in the MA program here at Purdue. We definitely heard from the department first so don't panic just yet. In-house applicants are handled first from what I can tell.
I am curious about the SLU acceptance, though, if anyone has any information about how they were notified of their acceptance!