How employer’s perceive the quality of particular programs is certainly relevant, but this is different from prestige. As discussed elsewhere in the thread, it also can vary significantly depending on things like location and past history with grads from the college.
I doubt that employers as a whole are emphasizing the name of the professor writing/giving the recommendation, just as they are not emphasizing the name of the college. Instead I’d expect they are focusing on what the recommendation says about the student. It can be difficult to get to know professors well at HYPSM type prestigious colleges… especially in the early years as an undergrad. Many underclassmen lecture classes are large, and opportunities can be limited for undergrads assisting professors with research or as TAs. The undergrad lectures are usually full of exceptional students, which can make it difficult to really stand out to professors. I wouldn’t assume it’s going to be a reference advantage over a less competitive college or that a well known professor is your best option when choosing who to list as a reference.
With the emphasis on relevant work experiences as listed on surveys, the most important references are often in a work environment, rather than an academic one. Hiring managers are trying to find out whether the potential hire will perform well on the job, not whether they know important professors. It’s an opportunity to confirm skills and experiences listed on the resume, and better evaluate the student’s strengths and weaknesses in a work environment.