That article is just a bunch of anecdotal evidence strung together.
So here’s MY anecdote: D1 attended a well-regarded private school that was by no means a powerhouse in CS. Her first job out of college was at one of those big-name companies, the kind of place that supposedly “won’t even bother to look at unsolicited online applications”. But they looked at hers, and hired her. Her salary was the same as (or even slightly higher than) that of her coworkers who were also new hires who’d attended some of those powerhouse CS schools. Second job was at yet another of those big-name companies; their recruiters follow anyone who made it to the on-site interview stage, even if they’re not hired at that point. When D1 did the on-site interview during her senior year, the other candidates in her group came from a mix of schools: some powerhouse, some not.
Feel convinced? You shouldn’t–I gave you one data point. One anecdote. The linked paper was just a bunch of anecdotes without any analysis behind them. So you should take my kid’s story, and everything that professor wrote, with a ton of salt.
Also, you gotta feel sorry for the professor’s students at UCSD. Imagine having your professor tell you that you’re just not going to do as well in the job market because you didn’t go to Stanford or UC Berkeley. Ouch.