@TopTier, I am familiar with PhDs and MBAs. The MBAs I know identify strongly with their undergraduate (BU, U of Rochester, Princeton, Penn, USC) more strongly than with their MBA (Kellogg, Anderson, Pepperdine, Wharton - guess it is both, but there was an MS from MIT in there in the interim, and the identification was more with UG Penn, Pepperdine). As far as PhDs, even UCBerkeley and Harvard are not as galvanizing for my colleagues as their undergraduates. The only exception in my experience is students that attended Exeter or St. Paul’s, where the Boarding School experience is the one that they feel really shaped them.
I could definitely see how a program, especially a cohort program like those used in professional schools, could have more of an impact, though.