This could be true (to some extent.)
This reminds me of one previous premed at an ivy (norcalguy) once said (likely semi-jokingly): I am a premed. So I am ashamed while I am walking on campus.
Why would a top research school not like to treat preprofessionally-minded student better? To put it more bluntly, there is a chance that if students (undergrad, grad, med school students, or even “career post-docs”) goes to a place where such students are ranked lower in a powerful research group, the kind of research job they may get is more low level (grunt) work. I heard that even for those career researchers (including research assistant professors, if they move from another well-recognized and respectful research institute to, say, Hardvard, even their job rank and the “nature” of the research job could be different.
It is all about the “fit” or “match” factor.