I don’t think employers for most part try to “adjust” GPA’s based on some perception of grade inflation or deflation across schools. However, employers do tend to hire from a limited set of schools where they have a sense of relative rank based on GPA and some factoring in of the difficulty of majors.
At the 2 prior firms I worked for, which hired nationally, the same group would do on campus interviews for flybacks, so we were looking at relative GPA’s from the same school before offering flybacks to between 5-10 interviewees. I personally took into account majors when hiring for analysts (for legal and banking associates there really wasn’t a difference in major rigor, although I had a bias for interviewees who had a quantitative background undergrad or subsequent work experience).