I have not heard this. It would not be good for pre-meds or adcoms. The objective of a pre-med advisor would be short term success rather than long-term relationships with adcoms. The LORs would be so heavy with bullsh-t that after a few years, one would come to distrust letters from advisor Y at school X. The proportion of students admitted from school X would decline and the advisor would go off to find another job. The long term relationships that adcoms form, sometime only by mail but sometimes through meet & greet opportunities sponsored by the med school for pre-med advisors of one's feeder schools would be no more as advisors would churn in and out of schools or in and out of the business.