I went to HS at the #1 school in my state in the early 2000s, and my experience was like GP's, not yours. Nothing s/he said was surprising to me.
Is this common? What's the measurement? State testing methods? Seems nebulous.
People have been true to their schools since at least 1963.
I absolutely don't think the ranking was meaningful, but it at least says something about how many of my classmates had affluent parents who put a lot of pressure on them to succeed.